Fights are meant to be fast. Making fights slower would mess even more the solo/small party play.

The chain system itself already reflects the desire of dev team in having full PT battles lasting no longer than 10 sec. IMO longer fights make the game even more boring...and i said this a few months ago...they should make bulkier monsters more part oriented (more resistent, stronger and rewarding more XP/kill when you compare to mobs oriented to solo/small groups fight)...pretty much like drakes and peistes originally were...mobs that were considered "too tough to solo" but that were killable in party and offered a better xp reward.

IMO they just needed to balance this a bit...the original coblyn rewarding XP even to monsters that would take 2-3x longer to kill was annoying. But now we are back to FFXI style...with everyone rewarding the same XP ppl will just seek the easiest fight. As soon as they balance the difficulty of certain monsters, they will migrate to another ones.