If they're really too close, all might be better off if you move them. With a little care, based on my own recent experience, they should be fine.

- Make sure the plants are well hydrated before you dig them up.
- Try to disturb the root system of the one you're leaving in place as little as possible.
- Remove some of the lower leaves of the one you're moving, and plant it deeply - tomatoes have adventitious buds on the stems that will form additional roots.
- Be sure you water and mulch both the plants that were moved and those that were left in place.
- The moved plant(s) will most likely sulk quite dramatically for about 24 hours, then will probably "get over it" and get on with life.

I recently found a volunteer tomato plant growing in the mulch by the curb, in very poor, dry and sandy soil. (This is where I grow those plants that are better off with minimal water and fertilizer). It even had a few flowers. I tried to save a decent root ball, but, sandy as that soil is, it all fell away, revealing a pitifully small root system. I removed several leaves and planted it deeply back in my raised bed vegetable garden and watered in well, fully expecting it to drop those flowers. Considered rigging up some temporary shade, but it was getting late, I was getting tired, and the oak tree provides dappled shade from mid-afternoon on anyway. It sulked for one day, then sprang back. Never dropped those flowers, which are now little tomatoes ... tiny and distinctly pear-shaped, so I'm thinking this may be from the yellow pears I grew last year.

You can also take tip cuttings of your tomatoes and root them for another whole plant. Surprising how quickly they develop roots and start flowering/producing.

Good luck!

OK, they're moving this weekend. Thanks!