I don't remember heroes being a strategy. Must be a new thing. While heroes are the core of a lot of strategies just saying "having high heroes" isn't an answer in anyway.
3 Golem+2 pekka+14 wizards+7 Wall breakers+6 hog riders
Clan castel 7 hogs
Spells - 2 jump 2 heal 1 rage 1 poison
i have been using against th9 with only AQ, without king.
last 10 attacks i did 30 stars, 3 star all time
As a TH10, I can 3 star most near max TH9s with either GoHog, HoLowiwi, whatever you call Golems, valks and wiz, and even gowipe with hogs or loons if its an open layout.
My go to is usually the GoHog, but depends on the layout.
not necessarily....my th9 gets hit by tens in war and from titans in matchmaking all the time, so far I have never been three starred in war and only happened twice in matchmaking since getting above champs in April. One thing I've noticed against other 9s though.....a gowi with 4 or more golems is realy tough for a th9 to stop.
My bk has been ug for a week so I just 3 star the top th9s in war with golaloon. Its super easy as a 10 with the extra camp space and extra spell. 2 gol, 3 hound, 7 wiz for funneling, few wb and 16 or so loons. Its hard to fail. My last hit I had an extra spell and 2 hounds not popped. still had a minute left.
I will suggest GoHo, GoLaLoon or even GoWiPe with 6 balloons. Extra troops and extra spell make most th10s able to 3 star any townhall 9. Never missed 3 star on a th9 since I got to th10.
Dont attack every th9 base with the same troop mix. The attack strategy depends on the base. Do what you were doing at th9 but bring a bit more of everything. As long as you dont have really high heroes some bases will still be hard on the first try.
The only difference is that GoWiPe is an option for 3 stars again as the pekkas are the only unit at th10 that have got a big stats boost and if the base is right, you just smash it like a th9 can smash a th8 with GoWiPe. If you bring some backend loons it gets even easier.
GoHo is extremely overpowered against most TH9 bases, just pepper the entire map with heal spells, hogs simply cannot die. Of course your kill squad must be able to defuse all dgb for it to work