I think in some cases yes, in other cases, forget it; every person is unique so you can't really say for sure.

The only way to know if you and another person "go together" is to try it out; date them and see what it's like! If you're both attracted to each other, why not? Though you're both subs, maybe one of you is more so than the other and one of you will just naturally wind up on the bottom more often; maybe you'll both switch for each other; maybe you'll find a dom to take care of both of you; who knows, maybe you'll both turn vanilla! (gasp). Kidding aside, human beings are very complex creatures and we can't predict ourselves, and you can't know ahead of time what will happen.

I do think a relationship between two subs might be more challenging in some ways, but then what relationship is easy? (I'm now trying to imagine how a relationship between two doms would work; I picture a lot of arguing, lol). If you're both willing to put into all the things a relationship requires: communication, hard work, forgiveness, willingness to grow and change, all that, then sure, it could work.