If your characters can't keep up in levels it may indicate that you're trying to use too many of them. Counter-intuitively, the game's easier the less characters you use as exp gets spread thin otherwise. Especially early on.

Another factor may be equipment, if you feel too weak an upgrade will definitely help, even more so than levels sometimes.

If you're short on money or levels don't hesitate to redo an earlier easy map a few times. Especially maps with +exp or/and +hl geopanels.

Anything in specific about the way you play or what chars/classes you use that can give us a hint on how to advise you? There are several approaches that you can take, though I'm not sure how inclined you are to use them. From more generic stuff like "just grind/powerlevel", to a change in your strategy and maybe playstyle. For example, the disgaea series in general favors a more offensive approach, to kill enemies before they can even take an action, especially later on. That's not to say defensive builds aren't viable, of course, it's just harder for the same payout.

There are some stuff you can do early on, like exploiting the Item World (though it requires some RNG) or unlocking postgame stuff through some exploits to get access to better stages/rewards, but either will break the balance of the main game. If that's not a problem for you, I can elaborate further later.

Other than what Tomberry Blue mentioned, other things that comes to mind:
- Magic is pretty good in this game (it has power, versatility and range), so it's recommended to build/focus on some casters. While it's not the norm in the series, elemental affinity not only reduces elemental dmg in general, but also affects the dmg output for elemental spells (Fire, Wind, Ice and their upgrades. This does *not* count skills in general). The basic tiers of Mages/Skulls always have good affinity with the element they use, but it's something to pay attention to when making other units or when reincarnating.
- In the Dark Assembly, raise the senators' favorability (Wood Golems, Mothmen and maybe Petit Orcs are the priority) with cheap, store-bought consumable items. Use cheap bills as well, like extorting their money or bills using Adell as a senator (you don't have to attempt to pass them, just leave to save a bit of time). It's a bit annoying at first (IIRC it takes about 1~1.5 hours or so to get them to a decent "level"), but it helps in the long run.
- Create some dummy units for non-combat uses. Even if you can deploy only 10 units at a time, you can have over 100 units in your roster, giving you plenty of room to have units made specifically for throwing your chars around (for mobility and having access to far away/isolated places), sacrificial units for lifting enemies or your chars to either waste their turns or tank a hit, units for inflicting status effects, weak ranged chars specifically for raising your bonus gauge etc. Heck, you can even create units for the sole purpose of dying, to either trigger or enable some endings. There can be an overlap on them so you don't have to create as many units (especially for the scapegoats, it can be any humanoid creature), and you'll unlock better classes as you play so they can perform better, but it's good to have an idea of what you can do/use them for. Examples:
> Early on, regular Warriors/Lady Warriors/Beast Tamers (if you've already unlocked them) are good throwers, with decent movement and throwing range, but Heavy Knights are the best for the job;
> Thieves' status skills are "broken", they are guaranteed to proc unless the enemy is immune to them (bosses and Marionette enemies), so they can be used to cheese a lot of stuff. Kunoichis have an "+" shaped AoE version of these skills and, even though they don't proc 100% of the time, they're pretty reliable;
> Beast Tamers have an innate ability to raise the bonus gauge faster (though IIRC it's not stated for some reason), but later on Kunoichis (with weights/critical HP) do the job better with their ability to sometimes act twice. Equip them with bows and keep them at relatively low level so they don't accidentally kill the target. Have 9 of them target a unit (the important part is to build a combo, just beware of counters) and either finish the enemy off with a strong char or disable them in some way, like putting them to sleep. This can be done on your own allies if you want (obviously don't kill them), it's just slower;
> While usually not very relevant, you can make up to 5 clerics to buff your allies (effect caps at 100% or double the base value). If you're in a safe spot with no aggro from the enemies, you can retreat/throw the buffed ally into the base panel, as buffs don't wear out while they're inside, to push for a big move on the next turn(s);
> For Item World runners (whose only job is to run through the gates), the best options are either Mothmen (possibly with a weight equipped) or the char you get at the end of this chapter. They have a natural high MOV stat (along with passives that captalize on it) and, more importantly, they can "fly"/move through enemies. Have them with as many shoes/MOV-boosted equips as possible.

Sorry for the wall of text (though I'm sure there's plenty more that can be covered), but I hope it helps.

Originally posted by Tomberry Blue:

If your characters can't keep up in levels it may indicate that you're trying to use too many of them. Counter-intuitively, the game's easier the less characters you use as exp gets spread thin otherwise. Especially early on.

Another factor may be equipment, if you feel too weak an upgrade will definitely help, even more so than levels sometimes.

If you're short on money or levels don't hesitate to redo an earlier easy map a few times. Especially maps with +exp or/and +hl geopanels.

This was a question I had - what exactly does the Exp reward at the end of a stage do - is it split evenly amongst all characters in your team (regardless of if they are alive and/or sent out)?

Originally posted by 68ST0X20:

This was a question I had - what exactly does the Exp reward at the end of a stage do - is it split evenly amongst all characters in your team (regardless of if they are alive and/or sent out)?

Not sure if the Exp get split ( doesn't matter anyway since you don't get much Stage Exp ) You do need to send a Unit out to get the Exp tough.

@TC : A Easy way to quickly get stronger is to just get 10 Levels in the Itemworld for the Weapons your Units currently use. Either leave then or continue hopefully getting a few Extra Weapon Levels.

Originally posted by 68ST0X20:

Originally posted by Tomberry Blue:

If your characters can't keep up in levels it may indicate that you're trying to use too many of them. Counter-intuitively, the game's easier the less characters you use as exp gets spread thin otherwise. Especially early on.

Another factor may be equipment, if you feel too weak an upgrade will definitely help, even more so than levels sometimes.

If you're short on money or levels don't hesitate to redo an earlier easy map a few times. Especially maps with +exp or/and +hl geopanels.

This was a question I had - what exactly does the Exp reward at the end of a stage do - is it split evenly amongst all characters in your team (regardless of if they are alive and/or sent out)?

Everyone on the battlefield (out of the base panel) so up to 10 character get all the exp in the bonus list that you unlocked. All of it. No split or nothing. It's not a very good way to level up tho unless you cheese post game maps (not recommended as someone mentioned it will destroy all challenge for the story) or on some item world trip but only if you get lucky with a lot of exp on the bonus list AND a good geo panels setup. So not recommended to rely on it either.