I'm not sure why you're telling us that, dude. Warriors Orochi 3 > all Musou that aren't Samurai Warriors 2 XL
Partner switching in OP isn't really a replacement for weapon switching for me. Problem with weapon switching in DW8 is the affinity crap. It makes the game too unpredictable and repetitive. See a blue icon? Kick his ass until you're doing that rapid move. Watch, as you deplete their life in 5 seconds, without a means to stop it. See a guy with an exclamation mark? Parry his attacks and build your rage meter. Then, when you get to an enemy officer, unleash your true rage, deplete their health in 2 seconds. Broke as fuck.
and in the case of the blue icons, takes control completely out of your hands. Equip a heaven type and a man type each stage, and you'll more than likely encounter most enemies as Man weak type. The affinities are awful.
Compared to One Piece's system where each and every character can achieve style action mode, its emphasis on dodging, and counters (if a Logia is logia mode, counter while in style mode). This makes it reasonably balanced, granted you aren't overleveled.
But this combined with the stage design, mission variety, and replay value of the stages (coins) make it kick DW8's ass.
I can tell this was by Dynasty Warriors Gundam team because of the interface of the maps. They're identical DWG3. They've REALLY improved since that game. It lacks the repetition of that game while still holding some of its core fundamentals.