Plum tree pruning help

These are my 3rd year plum trees, should I prune these bottom sucker's all off? Am I too late and should I wait until winter dormancy

If they're not causing problems (like poking you in the eye when you walk past the tree), you could leave them and thin somewhat next winter. Those are good branching angles for strength.

Ok I just wasn't sure if it was robbing from branches higher up or going to affect airflow and the open bowl type tree growth

You can look at them as a short-term investment. I see what appears to be spur development on some of them, so they might give you some fruit this summer. Then next time you prune, you'll probably take some or most of them away to improve the tree's structure.