Did 5e remove all that CMB and CMD thing? "Shove" sounds just like Bull Rush from 3.5e. I've been playing Pathfinder Kingmaker and I think the Trip and Bull Rush maneuvers are handled quite nicely. Each attempt is one standard action. The push back distance from Bull Rush is about right, I think. Don't know about other combat maneuvers, but at least, the mechanics for CMB and CMD seem solid to me (base attack bonus + STR mod + size bonus + misc mods, and all that).