Over agressive style doesn't have anything to do with handicap games, so why bring it up?
Aggressiveness has very much to do with handicapgames - at least in this case where white really wants to win !!
White needs to overplay and what is perhaps even more important he needs luck! Imagine some very strong prof. Goplayer
giving 3-5 Stones against a strong amateur. White will most likely come into situations there he can chose
between some sharp moves, hamete for example - that normally won`t work. Whether these moves work or not
depends on the knowledge of the weaker player, and not on the quality of the moves themself.
Because how can you differ between a 1d and a 5k if all you have are game results between players of equal strength?
WHY should i differ between them ?? If the 5k is able to play on 3 or 4 stones - so what ?
If you allow the input of handicap games you could see they each have a roughly 50% winning rate against each other if the 5k gets 5 stones. So with this you know both players are about 5 ranks apart.
I dont want to know how much the 5 kyu is apart from our 1 dan. I want to know if our 1 dan can play even against 1dans
and if the 5 kyu plays level against 5kyus.