On further reflection, morale and demographics may also pose difficulties to this plan.
To be a monk at all requires 9+ in their prime reqs, which means that ~30% of 1st level adventurers are qualified to be monks.
If you have a 9th level cleric doing your RL&L, then you need input monks with at least 16 Wis. This additional constraint drops the percentage of qualified 1st-level adventurers down to 1.8% (assuming all characters qualified to become monks become monks; call it a cultural factor). 1 in 12 characters are 1st level, so that means that 1 in 1 in 600 are qualified monks for this cult. If you need 1000 monks, then you need to be recruiting from a population of 600,000 people, or 120,000 families, and that’s making some dubious assumptions about distribution of characters among classes.
Perhaps a better avenue for the demographic argument might be through Domains at War: Campaigns’ realm-scale recruiting system. Treating 1st-level monks as Exotic mercenaries with a monthly wage of 25gp (per ACKS Core p51), we observe that in a Principality there are 77.4 monks available per month (at a cost to find them of 1750gp/mo, on average). Of those, assuming a +1 Charisma for your cult leader (they are a cult leader, after all, but still a cleric so Cha is not a prime req), only about 40% will enter your service, so you’re getting about 31 monks per month. Consequently, gathering 1000 monks will take almost three years, at a total recruiting cost of ~56,500gp (plus wages for the monks you hired from the beginning, which total another ~409,000gp if I’m doing my math right). And you will need permission from a prince to recruit in his territory for that entire time. Once you have 1000 monks, you will need 25,000gp/mo to keep them paid (curiously, monasticism doesn’t seem to effect henchman wages).
So: gathering 1000 monks requires about three years, half a million GP, and political connections.
So let’s say you finally have your thousand monks with +1 morale, on average (from your cult leader’s +1 Cha, recall). Every time you kill one of them to RL&L him, his morale permanently goes down by 1, because dying is a calamity. My simulations suggest that if your cult leader has only +1 charisma, you will run out of monks (in expectation) after six resurrections each. If you have +3 charisma (or +1 and Command), about 1.5% of your monks get stuck in a Fanatical loop, where their morale increases without bound (assuming that Fanatical results on loyalty rolls stack with each other), because once you have morale of +10 or so, you always roll Fanatical and the +2 from Fanatical more than offsets the -1 from the calamity. With higher input morales (from Command and similar), that proportion gets higher; about 29% become fanatical death-addicts at +5 input morale. At +2 morale, about 0.1%, a single one of your thousand monks, becomes a fanatic. This is, of course, ignoring any early “retirements” due to buildup of side effects. So… depending on your charisma, you may want more monks than you initially thought.
Continuing the +1 cha example, you’re also looking at difficulties making this process efficient in terms of time as a result of spellcaster availability. If you’re a 9th level cleric, you only get 1 RL&L per day. Bringing the process to its morale-failing conclusion involves casting on the order of 2000 Restore Life and Limbs, with a total market value of another million gp and (at 9th-10th level with a single caster) another three years of opportunity cost in adventures not taken (oh, and another million GP or so in wages for the monks as they gradually resign, in the best case). I suspect that with a budget of 2.5 million GP and six years of adventuring time, there are probably better ways to take over the world than producing one monk with 18 in four stats.