Agreed that would be bad. However, I expect that a "full attack" launch in Xsyon would be performed like that:
Place "Attack tribe totem" near to the tribe that is being attacked.
Set upkeep in that totem for stats increase.
Invite all players into that "Attack tribe" that want to participate in that attack.
--- Attack until victory (or what ever)
Dissolve Attack tribe.
Any player with more than 1 account can setup something like that.