Tinder End-Game

So Tinder is going well and I'm beginning to consider what my end-game is. I think the pleasure utility gained from banging as many randoms as possible with as little effort as possible is already beginning to enter the zone of diminishing marginal returns.

I think my goal right now is going to be to develop a steady rotation of friend with benefits type girls. That way, I can have pretty regular sex with a diverse group of girls with little effort who I get along with and who will maybe do my laundry and stuff while maintaining my somewhat fabricated aura of mystique that keeps them from getting bored with me.

I have 4 regulars right now (1 of which wants me to meet her parents and isn't as attractive as the other 3, so she'll be going once I get some more regulars). I have 5 girls in the to-meet pipeline right now. Based on historical data, I predict that 3-4 will flake. I also have been meeting girls on work nights, but want to stop because I like sleep.

I haven't had any attrition that wasn't caused by me doing something enormously douchey yet, but let's assume an attrition rate (they get bored of me or die or whatever) of 1 girl per month. Assuming I can add 1 girl per week to rotation and the end-goal is to have 14 reliable girls (seeing a girl twice a month is sustainable in the mid-term, I think), it would take me...

4(current) + 13(additions) - 3.5(attrition) = 13.5 goal close enough. let's assume one is an amputee

It would take me ~3.5 months to reach my goal. Let's call it 4 to be conservative. I realize I'm not calculating attrition properly, but it's more conservative and less work, so fuck it.
I'll be gone for ~6 months in October and I have no idea what the retention rate will be. Let's call it 40%.

So, March 2015: (.4)(14)= ~5 girls and we're back where we started more or less. I'll be better in every way a year from now though so let's say I can add 2 girls per week to rotation now. But I'll also probably be working and studying more... fuck it, 1 per week assumption holds. So does 1/month attrition

>>>
5 [current(03/2015)] + 9(additions) - (1/mo attrition) = 14 goal
2.25 weeks to goal assuming no attrition
attrition: 2.25 girls. Now need 11.25 additions

I don't know how the fuck to do this equation accurately, but let's go with this:
5 [current(03/2014)] + 11.25(additions) - 2.8(1/mo attrition) = 13.45 goal. still fucking an amputee. double amputee this time

>>> ~3 months from return to goal rotation: 06/2015 target date

Hold me to it. Watch me be married by then. lawl jk