Lets look at some things.
Rodelero and Peltasta skills are all usable while mounted. This is pretty clear in that they fall right into Hackapell builds and Hackapelle + Painguard provides permanent knockback/knockdown immunity for this sort of mounted tank to work.
Highlander skills except crossguard and carter stroke are also full available.
So if you dont want weapon swap. Rodelero, Highlander and Peltasta are your most obvious options.
Hoplite - Pierce, Stabbing and Synchothrusting are also usable with 1h Sword and while mounted.
the remaining 10 points can be put into spear Lunge or Spear throw. This does use Weapon swap but it is fairly minor
Barbarian - This goes back to what Ive said in another thread about those “forced” synergies being traps. Except for Pouncing. You don’t have any attack skills that are usable while mounted. There are two solid buffs, but everything else will dismount you and that is far worse than weapon swapping. Your ASPD is already naturally high as a Hackapell and a little improved stun on Helm Chopper isnt worth much. 15 unused skill points kinda makes Barb a lot less attractive as an option. If you dont care for the attack skills or don’t mind dismounting then you can still do Barb as Seism and Cleave are also there to use (while dismounted).
You absolutely can hackapell + Lancer and or Cataphract.
Rush for whatever reason isn’t available for automatic weapon swap. So this means making the 1h spear your go to weapon. However in doing so you will lose the 1H bonus off ASPD or Defense…just to use Rush without having to manually weapon swap. Given this is literally one skill, you could just manually swap specifically for Rush if you dont want to do that, then you will have your 1h/2h spear as your go-to weapon, and your 1h sword as your swap.
Cataphract - Acrobatic Mount will improve your Hackapell damage by 30%. Not bad. I already spoke about the Rush “issue”.
Templar - If I’m not mistaken. You lose out on Horse Riding + Advanced Orders. Everything else is usable on your regular mount. However not being to use your skills while horse riding blows and like Barbarian lacking mounted attack skills it is one of those “why?” choices with IMC.
It would be nice if ASPD actually applied to some skills because they feel sluggish now compared to when they were affected by Dex just a month ago.
So again.
Peltasta, Rodelero, Highlander, Hoplite, cataphract, Lancer, Barbarian are usable with Hackapelle. One could almost argue Doppel…but I wont.