I just looked at the other post first because I wanted to see a golden triangle palm. The question makes more sense, since triangles are single stemmed palms and these are clustering palms. Yes, you can remove the larger stems and keep the smaller stems. Removing too many stems at one time may tax the plant from the loss of energy, but just doing a few large stems every once in a while won't hurt a thing. You may want to treat, or seal the wounds on the cut stems to reduce the chance of fungus getting into the other existing stems.

Thank you very much plantsman56 for the help and advice.

I always like to thin mine out. It not only looks better but it keeps the aphids at bay.