It definitely is doable with small guilds, we reclaimed gilded hollow last night with a group of four (chrono mesmer, tanky-heal-support staff elementalist, dps dagger ele, and engineer) on teamspeak. It took a few tries, especially when we got some that were really far apart.
Some things that seemed to work for us (ymmv but I hope at least one of these helps):
- Stack on one of the vinetenders and aoe like mad while spamming stuns on the vinetender. The elementalist staff stun ring and the chrono evade wells really helped here.
- If we had bristlebacks the chrono would swap a few spells to reflects.
- Sometimes if it was far away we would let it fail on purpose so we would still be grouped and on the center island.
- We found that we could do most of the locations and burn the vine in under a minute when the tenders died. If it was looking bad on time we would often disengage and try and relocate to the map center using the rest of the time to clear some of the scarier adds.
- We kept restarting when we had a bad first position (far from the center).