The way I see it, it’s not the race points, and not OH per se, but the fact that Pax has so much of a magic advantage.
All the traditional races have a strong point, where there race bonus is higher than custom can possibly go. With Revalons that’s income, Science for Quantam, Speed for Camaar etc.
However, all those are basically ‘defensive’. Speed is grey-area, but ok.
The attack bonus for Wardancers is nerfed by the fact their speed sucks. But if you go fighter-running someone with Wardancers, you’ll see that’s pretty OP too - but it’s quite a bit more difficult to really abuse throughout the round.
Partax is a race with a crazy Magic bonus - with real strength against races typically made for banking.
The traditional -30% magic on bankers and attackers, against the 70% of Pax means you always have a huge bonus on a number of highly aggressive spells.
As to where for exploiting your attack bonus you need close proximity, and quite some intel and preperation, for spells you can do them anywhere anytime. It’s much easier to exploit it.
That goes for OH, but also for CPFF, e-storm, and even very easy things like vision.
The alternative for vision is SoT, and it doesn’t even come close to the power level of vision because it’s so much harder to succesfully perform, simply due to the bonus pax have.
Hence, I feel OH is not so much the issue, it’s the advantage Pax give that spell, due to their magic bonus, in the race-landscape the game currently has.
You can nerf OH, but Pax would still be crazy strong.