Holy Arms seems a bit underpowered for a very rare.
It's just +1 to hit on normal units, but not those with chaos channels and I don't think undead units (not sure on that though).
It also replaces rather than combines with Holy Weapon that will almost certainly be available to wizards with Holy Arms, so it doesn't improve your best units.
Also it can be dispelled in battle I think.
Compare to Survival instinct which although it doesn't work on normal units, it works on units with chaos channels and undead and the bonus is so much better +1 to hit, +2 resistance and +1 defence and stacks with everything else and cannot be dispelled.
It's also just a rare spell as well compared to a very rare for Holy Arms.
I would suggest changing Holy Arms to work on all units not just normal ones as a +1 to hit and be able to stack with Holy Weapon if you have it. Perhaps the name would need to be changed though.
It's just +1 to hit on normal units, but not those with chaos channels and I don't think undead units (not sure on that though).
It also replaces rather than combines with Holy Weapon that will almost certainly be available to wizards with Holy Arms, so it doesn't improve your best units.
Also it can be dispelled in battle I think.
Compare to Survival instinct which although it doesn't work on normal units, it works on units with chaos channels and undead and the bonus is so much better +1 to hit, +2 resistance and +1 defence and stacks with everything else and cannot be dispelled.
It's also just a rare spell as well compared to a very rare for Holy Arms.
I would suggest changing Holy Arms to work on all units not just normal ones as a +1 to hit and be able to stack with Holy Weapon if you have it. Perhaps the name would need to be changed though.