I follow Reinhardt (surprise surprise), in his build as well, you can use a sword and a shield, a pike, a horse and a lance. even a crossbow... what else do you want?
lately, thanks to random plains on pecores server, I've seen a lot of spontaneous tactics happening, and some nice cavcharges, if you can time them right, they're devastating, but don't let cav just run straight on enemy pikes.
infantry remains the backbone of any army. shielders, pikemen and crossbows. With those three things you can beat any enemy.
archers and cav are support, bonus cards, a useful addition, but not necessary
So for strat you should have a hybrid build, being versatile is important.