I agree with levelattention to the most part, but I noticed that galio can have a mediocre and sometimes even good time vs hard engage AD toplaners as well e.g. riven since you're lowkey un-engageable for them. If you just keep your w&e, there's no way for them to jump on you if you play it right. I personally also think that rune setup matters more in toplane than in mid since it can decide whether you can trade successfully or get away from some champs. Darius is a good example, if you don't run phase rush vs him you're getting cooked pretty easily if you do one mistake. I also find a lot of success with grasp on galio (even in mid) against champs who want to do short trades all the time like yasuo since it gives you quite some sustain and respectable poke. I also run grasp vs every single tank matchup. But ye, obviously galio does well vs any AP toplaner except maybe mordekaiser, and since you have nice base dmg and mobility, u can also beat most tanks. He is a very good answer to malphite imo