I'd honestly advise against making almost any of this raidwide (herald bonuses would be ok admittedly since only one is notable to begin with). Making Fellowship of the X raidwide is just a straight buff to second captains as you'd be able to chain To Arms raidwide for 50s of every minute. On Guard/Relentless Attack/Focus being raidwide again is a straight buff as you almost never want to run two Captains of the same line.
Without making to arms or the tactics raidwide, the meta will still be unchanged (not that what has been made raidwide already will change the meta anyway). You'd still bring two captains, one for each group, including to arms and tactics in the raidwide buffs and you completely remove any necessity on having two, because one can do all.