Google Pack, avast and compatibility?

Right now I see avast, Immunet and PC Tools Spyware Doctor with Antivirus in Google Pack.

Why all of them together, I understand avast and Immunet are compatible, but what about PC Tools Spyware Doctor with Antivirus, can all of them works together?!

Well it does allow the user to select what they want, but perhaps it should have a note on running two resident AVs on the same system.

That’s my point, Gpack is designed for amateur users (mostly) so they just select all option and click install…

I guess no one wants to rock the boat in saying offering multiple AV options isn’t a good idea as they might remove your option ;D