This is just an idea I had to diversify rolls within games for each class. Probably stupid but I figured I'd share incase it sparks inspiration for better/more refined ideas.
1. Assassin: have the ability to execute after raw light attack (unfainted) as well as able to execute in the minion lane/pikemen. Resistance to projectiles including balistas. Captures zones faster.
2. Vanguard: when the revenge meter is at 50% van can no longer be executed by a light attack. When at 80% full, vanguard cannot be executed. Resistance to Nerf feats and enemy buff feats. Ability to use enemy banners to heal. Can kill with a fast execution after a heavy finisher in the minion lane/pikemen.
3. Heavy class: has resistance to bombardment feats like fireflask, arrow storm, javelins and bombs. Shields last longer on them while they are in a zone. Revenge timer remains active only while enemies are within a given radius once popped while in zone.
4. Hybrids:
Execution animation via heavy attack finisher cannot be stopped by another enemys attempt. Cannot execute in the minion lane/pikemen at all. Time is doubled for person being executed to respawn. Hybrid does not regain health via executions. Hybrids are resistant to all stamina drain feats.
Respawn time: each class would have it's own respawn time specifically designed to balance out their abilities within game and adjusted in testing ground so if it turns out a class is more op than another class the respawn time is adjusted to compensate for minor differences to speed up the ability to Nerf or buff a class. This could also be done based on individual tier list placement.
If this could be used in conjunction with something like a gear overhaul (so that many of the best feats arnt locked into certain classes) would be good, although im also against the idea of re-spawn timers as a penalty as the truly broken monsters we have seen over the years would probably not get a timer delay for 6 months, then get nerfed and the delay at the same time.
Why not just have hybrid be a mix of the two classes that make it up. it can be a set thing for each type such as assassin/ vanguard or /vanguard heavy. that way each of the hybrids still have something kind of tailored to their types. its not as strong as the full thing but it is a more jack of all trades as intended.