pinicle and gallion with sloop backup and then maybe some C class and strafez
pinicle has a slow build rate but has the best pr to damage ratio in the game i believe meaning u get MUCH more bang for your buck with them.
gallion are great for under 100k, just spoam em usually and u will win with some sloop and pinical back up.
u may need strafez queens and runners wen u come accross herc, thor or hun li/rubies, just hit on aggressive with alot and u MAY win.
guard are the hardest race for collewctive to beatr and most just leave them alone cos the guard counter WILL take the full 3 from u if u dont expect it and they can easily out build you.
u need any other help PM myself on GC:RT or im sure Zeinth on GC:RT will also be willing to help with his guides he has writen in regards to collective stacking and starting strats