I don't know what this disagreement between you two proves one way or the other about baynes but if does prove a belief I have had and tried to argue, we will be fine starting with Horford as the lone Big against Embiid. I keep saying that Horford can handle Embiid just fine and that we don't have to start Baynes against any team in today's league, it's not as if Horford will be playing 48m, Baynes can knock him around when horford rests because it's almost assured, if there are no injuries, (healthy) Embiid will get more minutes than Horford because CBS doesn't play our guys many minutes if he has the choice, because we have a bench with players like Baynes and Theis who are solid NBA bigs who deserve some PT.
I believe if any player is being underrated, it is certainly Horford. I think the only reason Horford won't start as the lone Big will maybe be for preservation during the regular season and/or based on how Hayward does. I still believe Baynes won't start if everyone is healthy and playing well. Embiid wants no parts of Horford. Horford said he added weight (muscle I believe) this season, because he'll be the 5. There are only a couple centers where that matters and Embiid and Howard are really the only ones he'll see more than a couple times that fit the bill, but he changed himself for that. He obviously believes it will be his job against them or else he would have stayed the same, knowing Baynes would handle it.