This is something I see people do all the time. Don't have swampert as your "dedicated lead". The only playstyle that works for is hyper offence... against balance if you lead off with the obvious lead people are going to take advantage of you. Lead of against team matchup, not because you just don't want to take the time to assess the situation.
Also, you should take time and actually explain your sets next time. It's hard for people to help when they're unsure what you use specifically to stop specific mons, or why you're running specific coverage moves.
Hydreigon: Life orb hydreigon generally prefers either superpower or taunt over fire blast or flamethrower. This is a wallbreaker, and without either of the two you are walled by stuff like milotic, umbreon, blissey, etc.
Chandelure: Your team lacks priority and barring crobat is generally a slow team overall. My recomendation is you change this to scarf. Also... kind of a funny story, I once tricked a florges choice specs way back in the day and proceeded to get swept by it (long story, but that's the important past) so for that reason trick+specs is generally bad because you're giving their wall more utility than you want, IE specs vaporeon scald, specs florges, etc. Keep trick, run fire blast, and make it scarf (IMO).
Crobat: Cross poison is rarely ever relevent and generally redundant and inferior to brave bird. I reccoment either sky plate or black sludge, same evs, with roost over cross poison. Cross poison "hits faries".... which you already wall (even better so with roost) and for which you literally have an aggron for anyways.
Aggron: Aggron is weird here. It's generally meant to be the rocker, and I find swampert is really redundant. I think you should switch out swampert for some other bulky water (suicune, if you want my oppinion), suicune offers another ice resist, water resist, another win condition, and the electric immunity you lost means nothing because all electric types in the tier carry grass coverage and beat pert anyways. After switching to suicune, you can run rocks on aggron. oh also, run thunder wave. Your moves should be: heavy slam, stealth rocks, thunder wave, roar.
Florges: Ability should be symbiosis. Are you crazy? This is obviously the superior ability, and arguably the best ability in the entirety of UU.
Otherwise looks solid.
