2 Soldiers
1 Pyro
1 Engineer
1 Scout

The Soldiers will be for general killing and wiping out large amounts of robots, the pyro is for tank busting and medic killing (REFER TO LOADOUTS), Engineer for two-way teleporters and killing any stranglers that get past the Pyro and Soldiers, Scout for money collecting.

LOADOUT
for soldier there are two options, the basis loadout of Beggar's Bazooka, banner, and escape plan, and what i call the AC-130, which uses the Air-Strike, B.A.S.E Jumper, and any melee.
for Pyro, "just use the Phlog" -Weezy. Weezy's not kidding, the phlog is the best for tank busting due to the on-command crits. as for a secondary, use the gas passer, as Explode on Ignite allows you to kill Uber bots
for Engineer, use either the Rescue Ranger or Widowmaker, Wrangler, and either the Jag or stock wrench.
for Scout, use the Soda Popper (REFER TO UPGRADES), Mad Milk, and Fan-O-War .

ALL CLASSES: typically i upgrade all my weapons and then use the leftover credits for resistance. at the start you're gonna want to max out blast before moving to crits. but in the late game, get the rest of the resistances, movement speed, and health regen, jump height should be one of the last upgrades you get.

SOLDIER: no matter what loadout (except for the direct ♥♥♥♥) you should always by ONLY ONE tick of Rocket Specialist. for the regular loadout, you're gonna wanna have some ticks of reload speed, firing speed, damge, and HOK. for AC-130, max out reload and firing speed, and get two ticks of both HOK and damage.

PYRO: the first thing you should buy is Explode on Ignite, before maxing out damage, HOK, and ammo capacity.

ENGINEER: for Engie, get two-way teleporter, max out dispenser range, health building, and wrench swing speed. then get ONE tick of Sentry Firing Speed. if you're using the Widowmaker, max out firing speed, damge, and HOK if you can.

SCOUT: for the Soda Popper, get two ticks of ammo and magazine capacity, max out HOK, one or two ticks of damage, and the firing speed ghost upgrade (watch Weezy's underrated upgrades video to learn how to do it). for the mad milk ALWAYS get slow target. for the Fan-O-War, upgrade swing speed if you've upgraded everything else and can afford it.

PYRO
for Pyro, you typically wanna be behind the shed at the front left of the map, that way you have a safe place to throw gas from and do your mmph taunt, when the mini-crit Battalion soldiers come, you wanna be somewhere near the top of the hill so that the soldiers dont target you as much.
SOLDIER
for both regular and AC-130 loadouts, you wanna be by the large health and ammo pack at the large central building, as you have access to an instant refill for ammo on both loadouts and health if you're running the AC-130 loadout.
ENGINEER
typically you wanna have your dispenser next to the right fence at the top of the hill, with your sentry on as close as you can to the front with yourself in your dispenser's area of effect, with your teleporter behind the left fence.
SCOUT
you're typically gonna want to stay by the engineer's sentry so you can throw your milk from a safe distance before going in to collect money and deal some damage, other than that, your strategy is practically identical to Pyro's