5 Riding is definitely worth it. If you're going for 3 Riding, you're just asking to get killed.
21/15 is a good 1h/2h cav build, imo
2 IF
7 PS
5 SH
5 ATH
5 RID
5 WM
WPF distribution is up to you. I would go for around 120 1h and a little over 100 for 2h.
3 riding is very bad,and horse is very slow. You need at least 5 riding,but if u ask me i would ignore wm and if and make 21/18 or 18/21 hybrid.
i just wonder is 114 wpf in 1h enough.
I've actually done that exact build before, Tom, i liked it a lot and was doing great Cav v Cav, but this new build isn't exactly meant for being viable Cav v Cav or even against Inf, more just getting around the map quicker.
I'm still torn on what to put more WPF in or to just try to equal it out, my reason for doing more in 2h in the first place was that my 2h sword is what I have loomed, but i guess that could be used the other way around and require me to put less wpf in for it to still be effective.