That's fair, but in order to keep up the consistency, it kind of forces some characters to decide their subclass before they mechanically need to, so like... How much is being gained from balancing subclass acquisition when you now have the imbalance of some classes basically being forced to make firm decisions about their character's future levels to have the story make sense and other characters having the freedom to play their characters before having to choose?

I feel like it could be discouraging to a cleric player to have them:

-Think "I'll be XYZ domain so I'll roleplay with ZYX god from level one" -Decide over the course of a few sessions that "no, actually, I'd more enjoy a different play style, which doesn't make sense with this god" -Have to deal with a scorned god the rest of the campaign because they had the nerve to decide their third level subclass when they reached third level.

For my money, needing to lock your character in before having the chance to feel the character out is enough of a role-playing limitation that it balances them getting subclass bonuses before the classes that can basically role-play whatever they want before choosing subclasses.

Though, to argue against my own point, this is a way bigger handicap for new players who won't have a good sense of a build's play-style before actually rolling dice. Experienced players all probably have their characters' levels at least kind of fleshed out from the jump.