Now your on the right track. I had hesitated when you first asked about "raising queens to cage".
Although some do purchase virgin queens, the vast majority of queens are raised, mated, and sold as previous verified laying queens. The way to do this, is have a nuc for every queen, get them mated, then cage, sell, ship, etc.
The haircage roller to me is for last minute emergencies. When time is short and I can not get all my cells into nucs before they possibly start hatching. If they do, and as you questioned earlier, they will kill each other off till you only have one left. I think having the queen cells in contact with bees during the whole process, provides and develops the best queens. So the goal is to time everything out so each queen is raised, and placed in individual nucs, without such things as roller cages, and incubators. Of course incubators and such as needed if you were doing A/I-A/A. But for the open natural mating, it is best to have each queen cell in contact with bees, open in the nuc she will be laying, and let the bees do what they have been doing for a long time.
If you graft and produce 25 queen cells, then you should have that many nucs/hives for them to go in.
A/I is a possibility if you wanted to go that route. But it is usually used in situation of raising breeder queens, controls research and genetic isolation, etc. It comes with an increase in cost of production, and also increased risks and damage to queens. For what you sound you want to do, plan on having mating nucs for each queen.