I liked Tommy well enough and not only is he a former coach here, but he is an alum so I will always root for his success anywhere he goes (unless that's Green Bay, Wisconsin; Chicago, Illinois; or Detroit, Michigan).
He was not the best OC we ever had, but he certainly wasn't the worst. Good to borderline great at times playcaller and gameplan developer, bad to middling recruiter. Better OC than position coach imo.
As for Hartline, the best WR coach in the entire country and it's not close. Does that make him a good OC or potential HC? No, not necessarily, but he is far and away the best WR coach in the nation. People can say "oh it's OSU, they recruit themselves" and they're not wrong but that is way underselling what Hartline has done there. WR U was LSU or for a period, Bama until Hartline got to OSU. If it was so easy to just recruit and develop high level WRs to OSU then someone would have been consistently doing it before he got there. He's elite at scouting and finding high level recruits and then recruiting them to play for him, and then holding up his end of the bargain by developing them and putting them into the first round of the NFL draft where they also go on to produce. I get Jigg seemingly wants to make Hartline into some referendum on morality because of his association with Urban Meyer but Hartline has nothing to do with that.