Sounds like you are where i hope to be in about a year with my beer except i probably dont have the space to do 13. I will porbably stay topped out at 8. So what kind of kegs are you fermenting in? Also what is your yeast process. Are harvesting from the bottom or splitting your starters?
I've changed my process recently to do brewing in sprints. I'll brew every 10-12 days for about 6 weeks until every keg is full, then take ~3 months off.
I have a conical now. I used to do cornies. Same idea just different volume.
My yeast process is to buy 2 fresh packs, do 2x1.8L starters and let those go on the stir plate. Then i take the slurry and pitch to 4x1.8L. THat yeast i'll then pitch to the smallest gravity lager in my run. After that i just take the slurry and repitch it a few days later. Slurry older than a couple days sucks.... it HAS to be fresh (like 5 days max). Also if you spund you can extend that a little because the yeast is still active for a few days after you rack.
I save a TON of DME this way and a TON of TIME making new starters for each one.