It seems to me that most human players do not know how to play humans correctly. That's why I'm here to give a few tips on how to best make use of the humans.
1 : you only need to kill eggs, overmind and grangers to win.
2 : cf tip 1
That's all. Kill a Dretch, buy painsaw + armor for 170cr ( you got 175cr for the kill ) and run to the alien base to kill eggs and om in that order if possible. If you kill at least 1 egg, you are positive on cash ( you get around 200cr per egg kill ). And by all means, do NOT stop in the way to kill a dretch. Remember that humans are very dependent on their base for health and ammo so each time you stop to fight a useless dretch, you'll lose some precious health and ammo which means less time to kill the real targets.
Here's a demo to show how it's done. Too bad I haven't one with very good alien players around too but they can't be everywhere anyway so it works for that too
And if they stay to defend the base, it means they aren't attacking yours.
http://tremulous.free.fr/demos/demo0032.dm_69
Eggs are 150 credits I believe.
I think the effect you were going for was:
http://rapidshare.de/files/23364505/atcs.dm_69.html(second time around didn't get to do it. got a phone call and came back to next map... looking at the demo, I guess the builders didn't listen to me :x.)
Saw rush can be very effective, but trust me, builders learn and expect them

. They're alot more fun at s2 with grenades, used to get tons of grenade kills everytime I did it, but once again people learned

. For example most builders will put two tubes to block the ramp on ATCS up to the OM, but a grenade or saw can take them down, or sometimes they can be jumped over if poorly placed.
(Was hoping to make that demo into avi and put it on Tremulous demo thread, but my efforts into making a reasonable sized avi failed...)