There is a really great leveling guide for a 4* rainbow team and it mentions TC3 
I adapted it for me until I was at TC 19, and now with TC 19 I’m always out of food (2000 recruits stored in TC11, about 2000 rugged clothes…hmm and now, burn it - but where should all the feeders go? Big problem, hehe).
That’s something for the future: if you go to TC19 and have a good amount of recruits and rugged clothes, having the farms at level 12 is not the best decision 
Maybe it’s useful for you, too…