>>53857534guy who actually made the initial post here
I haven't watched any analysis videos but I have played the games. it's perfectly feasible to juggle a team of 5 pokemon, I've done it and I didn't have to grind hard until I hit the league. this is because of the previously mentioned badge boosts and also the trainer rematch system which, while not entirely within your control, is easy to understand and use.
HGSS do not have these safety nets. there's no badge boosts, and the rematch system is so stupidly specific that even with a guide you'll have a tough time using it. if your team isn't up to snuff, you're essentially forced to KO wild pokemon for about an hour, maybe more. forget about training a full team, you'll fall behind with a team of 3 or 4.
this is genuinely such a big issue that HGSS remain the only pokemon games that I've never finished.