Tomatoes don’t like wet leaves, but they *really* don’t like splashed leaves. After they get tall enough, any leaves below a foot from the ground need to be gone. Like you said, any mulch which clumps enough to shed the water is a problem, but as long as you don’t get large mats, I’ve found leaves to be fine - and even better if they’ve been run over by the lawnmower a few times.
The main tree in our house yard is a HUGE (and I mean you can see this thing from SPACE!) Maple tree. When she sheds her leaves in the fall, the first three rows of my garden beds are covered. I just let them break down over winter; they are a great soil amendment.
That tree is also home to all kinds of birds (two Oriole nests in there, this year) and she gives wonderful morning shade for working in the garden, but you’ve only got until about 11am to get everything done for the day. The garden is, ‘ All Sun Until Sunset’ from that point on. ;)