since there is that new feature with heavensward which allows you to run all old ARR content which includes coil you can go with less than 8 people and dont be ilvl or lvl synced at all. then faceroll it with 7 lvl 60s. i bet most skills will do little to no damange because of the level difference (except heavensfall or dives pushing you into the wall^^ thats likely still death with 60) i wouldnt worry about coil anymore at this point. you dont need t13 clear to join the new 60 raid later.