I feel like their needs to be something else for the marines to do in the early mid game.

Right now its defined by two tech routes.
1 - Armor Weapon Upgrades
2 - Phase Tech
3 - Turret Bay

Generally you cannot pick two of these options with a moderate flow of res.

What about lighter upgrades like a Short range scanner grenade that costs 1 res or is even a permanant upgrade that reveals small area's when thrown.
-This would help counter act stealth options

I cant assume this would help at all but, I just wish they had a few more options. Especially from a marine team that has trouble killing lerk or even skulk. Give people more to do? I dont know, just a thought.