Absolutely no worries!
From IC:
FYI, the reason I did it this way is that Benny is not proficient in arcana (-1 ability modifier), whereas Max is (+4 modifier). I RP'ed Benny's higher roll to justify it. I have no issues just having Benny roll with advantage: it makes sense since he's the one that has detect magic active (so actively conferring with Max to get his opinion, but Max not seeing the auras). Note that in the future, without having detect magic, it still would make sense to me (and would be statistically better) for separate rolls if both are observing independently a magical effect.
But... you're the DM so you're the boss! ;-)
And, I gave Benny a 12 in wisdom because the theory-crafter in me felt that this would be a cool setup for a MC cleric dip at higher levels. For example, getting a half feat for the 13 wis and getting a level in knowledge cleric for expertise in Arcana and perhaps religion would be hella cool!
Cheers,
SG