It's appropriate to genre/myth/legend/folklore heck, even RL beliefs, historically. Many an emperor/king/whatever has claimed divine favor... most all, really... Pharaoh claimed to be gods...
We assume Gods exist and empower Clerics/Paladins at every table, that there are extradimensional beings wanting to make pacts with would-be Warlocks at every table, that there are sorcerous-power bestowing wild magic events at every table, that there are Orders of Druids or Paladins in the setting at every table.... every class brings with it assumptions.

"hidden blessings by the gods" isn't any worse than those brought in by Cleric, Paladin, Warlock or Druid... Sorcerer seems to have more of a range.
So something like, "...super-human potential from some source, perhaps the Gods themselves, the meddling of some not-quite divine power, a warp in the Weave, perhaps a Destiny the Gods themselves are unaware of...." would be even better. But, for a religious setting "blessed by the Gods" would work, even if it weren't accurate.
I expect they'd be a handful. Stark is arrogant and flippantly domineering, Barton ...has issues.
I'd rather have the Beast & Nightcrawler as players.