Remathilis
Legend
It's why the whole "strip the classes down to 3 or 4" idea rarely pans out for long. It's very limiting on possible PCs types unless the DM adds classes or house rules OR allows players to all run unicorns.
On a macro-level, saying "we only have 4 (or 3, or 2) classes and a bunch of subclasses" seems reductive for the point of reduction. For example, a Druid and a Cleric are both "priests" but their isn't a lot shared. They don't share weapons and armor, roughly 50% of the spell lists are different, they don't share class features (channel divine vs wild shape). What exactly is gained by combining them? You'd either carve out so many exceptions that they end up separate classes OR you merge them to the point that are a generic soup that link the distinction between them (compare the nature domain cleric to a land druid; ask if the former could replace the latter).