Very good point, but I don't think it'll be a problem.
I have a parameter in LOGIC.TXT (releadmax in the difficulty_k section) that specifies the max leadership allowed for rebirth based on difficulty level.
Here are the current values per difficulty level:
1. Easy = 10,000
2. Normal = 5,000
3. Hard = 2,000
4. Impossible = 1,000
These values are easily changeable, but I think those are good first cut values (I could also (roughly) halve them, which I've heavily considered).
By the way, as an aside when it comes to my modding (if you haven't realized this already) I do my best to put limits on a feature that I implement, if it's possible, and add knobs to turn to adjust that feature accordingly.
The deal is, though, that even though the maximum Leadership is higher than it was originally, there was nothing preventing you from doing this in the original game and since you always got the same army, it was in fact much easier to do even though you got fewer troops.
You could easily set up a place where you can travel to rapidly, die, pop your rebirth troops into the Debir castle and then run to any enemy stack and die again to repeat and build your forces.
The only thing negatively affected is your score if you do this, but if you don't care about that then you can use this strategy.
Now, with all the variability that you've mentioned, it will take much more effort to garner an army with a consistent set of units. Just take the unit list and the number of slots and you can get a good idea of what the probability of getting a certain unit type is.
Here are the number of units available for each class:
1. Warrior: 73 (66 if playing on impossible due to all the level 5's (except Ogres) being over 1000 Leadership)
2. Paladin: 42 (36)
3. Mage: 48 (41)
The Warrior has the most unit choices and the Paladin the least so the Paladin would be easiest. Here is the chance of getting a particular unit for the Paladin: 1/42 + 1/41 + 1/40 + 1/39 + 1/38 = 100/799 ~ 1/8 (1/36 + 1/35 + 1/34 + 1/33 + 1/32 = 85/577 ~ 1/7 on impossible). So playing with the Paladin, you have about a 1 in 8 chance of getting 1 of the armies you'd like to grow (or 1 in 7 chance on impossible) with each successive death. However, if you'd like to get the same 5 units to grow, your chances now are (note that probabilities are now products instead of sums): 5/42 * 4/41 * 3/40 * 2/39 * 1/38 = 120/102,080,160 = 1/850,668 ~ 0 (5/36 * 4/35 * 3/34 * 2/33 * 1/32 = 120/452,339,040 = 1/376,992 ~ 0 on impossible) with each successive death.
These are very low odds for getting all 5 troops (and they drop even more for Mages and Warriors). While I think it may be possible to grow 1 or maybe even 2 troops with successive deaths if you have a lot of patience I think trying to build an army of the same 3, 4, or 5 this way is going to be a lesson in futility.
So I'm pretty sure this is going to be okay, but thanks for pointing this out!
/C\/C\