Here's the Monstera. To prune or not to prune?

The plant you have there is Schefflera arboricola. I would not recommend planting them together for a variety of reasons. First, they probably won't be quite as happy (at least if they are really two different plants, as opposed to cuttings from the same plant). When two different individual plants of the same species are planted together they sometimes suffer from slight (but often noticeable) allelopathic effects. Second, the individual plants can be pruned, and would then grow into more full and pretty plants on their own. Your second one (on the viewer's right) is already reasonably full looking. Third, you probably couldn't plant them close enough to look all that great anyway, without significant root work. I wouldn't say not to combine them, but I would say that it's not what I would do.

P.S. .....

I have a pretty good idea about how I would deal with the Monstera if it were mine, but I don't feel qualified to give someone else advise on it. If you don't get a satisfactory recommendation here, ask in the House Plants Forum.

Here is a link that might be useful: House Plants Forum

Thanks so much Brandon.