We use tumbler bins for composting a large amount of compost but we also have several of them and it is a small part of our soil mix. We have large worm bins that we use to produce quality castings for planting mixed with a small amount of our compost. The tumbler composters are nice for smaller gardens but they are fantastic for prepping worm bin food. I toss several bags of cut grass, some 5 gal buckets of food scraps and a bucket of rabbit manure for a week in my hot composter and let it cook down while getting a nice mix. After a week it goes into my worm bins and I pack that side full again for the next week. I produce a little over 200 lbs of worm castings a week now so I have plenty to plant with along with sell. Have you tried worms? You can start with a pound or so and let them start multiplying because they do very fast. You can also toss your extra worms to your chickens when your bins are full or you could even start raising mealworms for your chickens. I have started to write a few articles on those things if you are interested. Really nice job making the bins though out of what you have available.
It sounds like you do a better job then we do.
I took what I was dong for my homestead and started to run it as a small business and then grew it a little more and little more as I went. Now it produces well for my homestead and also helps bring in a small income. I have plenty of other projects though on the homestead that are good ideas I just did not have time for and did not find functional for my homestead similar to how composting was not practical for your homestead. That is what I love about homesteading because everyones homestead is different based on location and the person managing it's needs.