Arcanist School Understanding-Necromancy

[Lynceus]

By taking the Arcane Exploit: School Understanding, the Arcanist gains one ability of a Wizard Arcane School, and uses it like a 1st-level Wizard. If one were to select Necromancy, and take Power Over Undead, you can use Command Undead just as a 1st-level Necromancer can.

Further, you can expend a point from your Arcane pool to consider yourself a Necromancer equal to your Arcanist level for a short time.

My question is in regards to the limits on the power of undead commanded. Command Undead states that "You can control any number of undead, so long as their total Hit Dice do not exceed your cleric level."

So without spending a point from your Arcane Pool, it seems that you can only control 1 HD of undead at a time. By spending a point, your "wizard level" increases to equal your level, but only for a number of rounds equal to your Charisma modifier.

So what happens when the effect expires? Does your limit on undead you may control revert to 1? This seems to make the ability painfully limited for an arcanist, but I'm willing to accept that Necromancy is just a bad choice for this exploit.

(Power Over Undead, as it's written on pfsrd, never states that a Necromancer uses their Wizard level as their Cleric level for this limit, although I assume that's implied.)

[Claxon]

I believe you have a correct understanding of how it would work.

[Drimoran]

It is not a bad choice, if you use them when you have to use it. If you want to have an undead companion, it is indeed a bad choice, but you already have the command undead spell and animate dead spell so... Why don't you save such an ability for a desperate situation? For fighting. Save it to make skeletons fight each other instead of your party. If that's your use of the ability, it is not a bad choice. If you want an army, there are other choices.

There is the school savant archetype which gives you full access to a Wizard school.

Also if you have that exploit and then take one level of wizard, then you have full acces to that Wizard school.

But really, Command Undead (not the spell) is not the best tool to keep an army of undead. You have 1HD level, while animate dead is 4HD level. And Command Undead spell is 1dude/spell, that lasts for 1day/level (2day/level with Undead master feat). Having this in mind, I would never use Command Undead feat as a way of having an army, but as a combat tool. So it should not be a problem. I say it is as good choice as if you had it with your character level. It is a situational tool, for situational uses. And that's what your exploit do.