I want rival guilds to fight
So you ally the only other guild with active members that would pvp. You also attempted per your own post in your new player appreciation thread "to foster a stronger alliance" with BR/had a non agression pact which on a pvp server is close to the same thing.
BR or INC#2, depending in activity
BR or INC#3, depending in activity
ROK#4(actually close to the #2 spot, they're better skirmishers than INC/BR, just poorly geared)
#6, there is no #6
Honestly ROK should be #2 due to amazing skirmishing capabilities. /sarcasm off.