Unrealistic = already too much. It is still necessary to make them weaker than liches. But not so much that the choice would be obviously in favor of level 5.
Change the percentage of all necromancy???
There is another idea. Give the tent a low initiative, but make it infinite.
It would be easier to simply resurrect all losses after the battle if there is a tent and the corresponding perk.
However, in my mod, I gave the tent 5 or 6 shots, no more. This is a compromise between making the tent not run out too quickly in the final stages on the one hand, and not dragging out the battle too much on the other. This is with an initiative of 10. If the initiative is reduced, then the ammunition should also be reduced proportionally so that the total duration of the tent's operation does not exceed 5-6 rounds. IMHO