If the 4th slot is up in the air, go with a rog, your quad lacks dps. rog is the undeniable king of sustained dps,

cleric has heals, enchanter has slows/cc/haste - shaman/druid are redundant.

If your quad plans to run as six, go shaman and hope your lucky to find dps for the final two slots.

But 4man is great xp and can pretty much handle all group content with tank/clr/enc/dps

Enchanters can charm pets and do more DPS than a rogue, so can druids in certain zones. Druids can also make charming safer/easier for an enchanter using snare. A shaman is less essential to this group since there's already a healer and someone who can slow/haste. You can say "Shamans can help charm with malo" but a druid would provide transportation which can literally save you hours of time if you have bad luck or play during off hours. A druid can also save your group from having to ever do CR's with evac, and can pull in most outdoor zones with ease.

Shamans ARE legit, but for this particular person's set up I'd go with druid (or another enchanter for dual charm pet badassery) if just for the ports, or maybe a wizard.

yeah so in a 4man, enc is main dps/slower/cc .not terribly efficient. especially long term.

If the group HAD to 4man and for maximize dungeon crawl efficiency tank/clr/enc/rog can't be beat.

hate to break it to you but druids are just a nice tool . not the best at anything.

If you want a nice long term 4man - you want the most efficient class at their job in each slot.