Gimped by strong units (availability and leadership)

[Cabezone]

You have to do the caluculations to see if the tradeoff is worth it. If you can have 50 of a lesser unit, but only 30 of an upgraded version do the math. Perhaps the stack of higher units does a bit less damage, but they may have a lot more hitpoints. So they're less likely to die and retain high damage output longer.

It's all a bunch of tradeoffs.