With soo many humans running a hallway, a wallwalking dretch can rack up the evolve points pretty quickly:-)
The danger with the base strategy you mention (which happens A LOT on sst) is that base defenses are spread and thin. I go adv mara, jump countless, but spread thin defenses, and take out def comp or aim for reator. It's very effective on SST.
Also, with the plethora of humans on SST, and spread bases, noobs get used to A. camping around turrets/Tesla and B. Shooting around base structures, which isn't a problem until an adv mara is jumping around the reactor ;-D
Humans on SST have become experts at camping out a draw, or spamping as I like to call it. Camp base defenses to the point where you are base defenses.
Also, bases so spread are most vulnerable to repeater attacks, which is what I aim for. Forget the turrets, arm, whatever. It's all useless without the (FAR from base) repeater. Massacre ensues as I inform the dretch/noob horde that the forward base is down, even though I've just been killed. Time it around SD.
edit: I'd like to add, I can't count the times I've found a path to core human base and found an unprotected reactor, etc, while there is an army of teslas all around the alien base. Gotta have a remote egg!
further edit(last one, I promise):I think it's the high build points that unbalance SST, it encourages poor/sloppy base design and camping.