I think the funny part about multiclassing is that if the new system was designed to make it easier for casuals, they are actually making it harder since the restrictions were kind of a guard rail to prevent people from making inherently inferior builds. Ultimately, through playing and gaining 'experience' as a player will they begin to learn more about the mechanics. I mean sure, they will also learn by making builds that are ineffective too.
The caster progression is just gravy, but either way, respec is in so it doesn't really matter what you do, you can always fix the situation for a paltry amount. Fifth edition was designed to be as accessible as possible, and a little exploration of the PHB shows that it is pretty accessible once you learn a bit of it.
I still don't understand why they did hirelings this way, do they really assume that people would find it preferable to rolling their own characters from scratch? Is this some kind of accessibility feature for consoles? Can you respec them, yes, but now you are incurring a fee, albeit a tiny one at 100gp, to basically make your own. Baffling, I must say.
