It seems to me that the problem is the actual musician pool at where you are. I live in Nashville and if you hire musicians here, they will show up on time, play great and then go home or to the next gig, but they are not cheap. You won't get them to do 3 weeks of rehearsals 5 times a week for 2 hours a day, that would cost you millions
But the guys here don't need to rehearse more than once or twice for a live gig, unless you are asking them to do certain physical moves in cooridination etc. For studio sessions the guys come in, see/hear the material for the first time, sit down and play 10 songs in one afternoon, and it all sounds great. Again mucho $$$.
I think what you are looking for is more of a "real" band situation. 3 weeks 5 times a week is a major comitment, which nails them down to almost just your project, so they would have to make enough money to pay their living expenses in full, otherwise they have to do other jobs for their income and that's where the "being late" comes in.
Have you considered to move your project to a city where you CAN find good, reliable musicians. If there are no goods at where you are, move to where the goods are. Again, I think your main problem is the pool of available musicans in yourt area.