OP- I think there is much more to this progression than you have listed, but I know that you know (haha). The real awesomeness of ME 3 multi-player was team synergies and character combo explosions and if you look at the spec page you can see two characters available for spec points. In single player I suspect you can switch to them on the fly, AND hotkey your squads powers in some way, to achieve that effect. So you really have to think about your squads composition and it's synergies for different enemy engagements.
ME3 multi-player added more complexity like (the obvious) having 3 shield types (barrier, shield, armor) and then finally health. There was also more subtle mob vs tank mechanisms, aka, spec for maximum damage on one enemy, or area of effect on many. And that is just scratching the surface of combat complexity from ME3, which is surely expanded.