2.15 lowered the sync for all guildhests by one level because more players were starting to do them with high level gear. It's meant to increase the difficulty some, so it's all intended I guess. If you do it again you'll probably want to cross class flash so you have an AoE enmity grab in there.

"Due to the increased participation of level synced players, completion of guildhests has become easier than anticipated. To restore game balance, the level cap for all guildhests has been reduced by one."

Source: http://na.finalfantasyxiv.com/lodest...ba39b67875a7af