Idea:
Relating to my earlier post, this is how the transports would work:
APC: Lightly armoured, carries the most troops, one weapons slot. Essentially a big glass truck. Really fast.
IFV: Armoured, carries the second most amount of troops, two weapon slots. Fast.
AFV: General fighting Vehicle, carries a less-than-mediocre amount of troops, two weapon slots. Fast-ish
Tank: Heavy fighting Vehicle, carries 3-4 soldiers, two weapons slots. two weapon slots. Slow, but it's a freaking tank.
Air vehicles would be more expensive, but worthwhile.
But then this would mean alien ground vehicles as well since it wouldn't make sense that an IFV downs a battleship... Well my idea might not be a good one, it's something to work off of. I'm going to keep an eye on this. For science.