Four's too many.

I planted a whole four Tomato plants, all different varieties, two "grafted" as an experiment. Grafted ones, reputedly, are more vigorous than ungrafted. Not too sure yet, but I'm nearly having to cut my way in with a Machete. I'll lay the biggest out on the lawn to see how big it is - eventually.
I'd removed 3-4 off this truss before I got the idea to shoot it.
Wait till you see the size of the not-even "Beefsteak" ones.