I want to thank everyone who chimed in with their advice.
I am not much of a proponent of grafting, but it certainly is an option, and one that I will likely have to resort to in order to maximize my Eugenias' fruit production.
Brian, I like your idea of two plants of the same species in one pot. I just wonder whether, since the plants are not exactly the same size, there would be an issue of one plant overpowering the other? But, I think I might try that idea with a couple of Eugenias.
Elouicious, it sounds like we are in the same situation as far as our collections overflowing our limited growing space. I've tried avoiding dioecious species, but like you, for the ones I have in my collection, I don't just have one; I have four or five. It doesn't take long for that to add up as those four or five, easy-to-keep little seedlings turn into four or five unruly plants growing every which way (and refusing to fruit).