Well, I think that those two squash plants could end up taking up your whole yard! It'll be fun to watch them grow.
My advice would be to plant one centrally located plant next year. But, you should be fine the way you have it. The squash will most likely fill the whole container, intermingle, and spread around the surrounding area.
Plant some Beans in your container as well with some poles for them to grow up. The beans will help feed the squash.
Feed the soil, not the plants.