What is your global post-battle soul modifier? In most cases, you should simply get the number of souls displayed on the in battle resource counter at the top of the screen times (Necromancy is already applied to this number) times the global modifier displayed on the map screen. If you had, for example, 100/100 at the top of the screen, and a x2 on the map, you should be getting 200 souls. If you had an 87/100 at the top of the screen, and a x2.3 on the map, you should be getting 200 souls.
On PC/Mobile there have been instances in the past where the resource counter at the top does not match the actual souls you are earning due to a troop with necromancy dying before you can get off all your soul generation casts. The counter will increment your souls as if necromancy is applied, but the actual amount you gain is less.
Those claiming 325 souls per battle are using three necromancy troops, all surviving until all soul generation is finished, getting the full 40 base souls (x2.5 both per cast and to the cap from necromancy, displayed as 100/100 at the top of the screen in battle), with a global modifier of x3.25 (usually, +50% guild statue bonus, +100% armor bonus from celestial or DK armor, +75% from Warlord I difficulty and playing a challenge). If your global modifier is only x2, though, the most you’ll get is 200. I have no idea why you would be boosted to 200 if you are only displaying 87/100 in this case, unless your soul counter doesn’t update on the final cast (PC/Mobile soul counter doesnt update until after the full spell and any board mod resolves, but it does resolve before battle ends).
Potential glitches aside, that team seems like it would take a decade to finish any match using only two colors and having your only damage source either exposed in front or heavily mana blocked. Even early on, unless you are literally still on your first quest line, you could probably get the same amount of souls faster by occasionally using Tyri in a normal team and knocking out about three treasure maps when you eventually get them. Once you get a solid team up and running, you’ll probably just want just wait until you can at least level all the magic bonus kingdoms to 10, then use an incidental soul generator in your main team like Valk, Banshee, or Wight (console has those changes, right?) for trickle gains, supplementing with challenges on the highest difficulty you can muster if you want to level a specific troop, and putting off straight farming as long as you can as it becomes much faster later, especially if you manage to pull The Dragon Soul.