In that case, all the above rules still apply, but insert the next one as Rule
#1.

Rule #1. Bots of the same class make life easier.

I once tried a Warrior, Healer, Shaman, RM, SM, BD, BD, Skald combo in DAoC and it ended horribly.

And remove rule #4, as it doesn't apply. Doing instances with 3 people is possible once the mobs are lower than you are (assuming you're a good player).