As a tank, I used to only pull a boss in CT after doing a ready check, but now I feel it's unnessecary. It is rare, almost impossible, to have all 24 strangers consider themselves ready simultaneously and that in itself isn't needed, all the fights can usually be beaten even missing a good many in the alliance. Instead, I pull when it looks like most players are in place and this is easy enough to tell by looking around, no ready check required.