So who is responsible for this apparent turn-around? 
Ofcourse its Ron. All its taken is a few major decisions, decisions the other guy would have flaked out of. For example 'do we run the experimental rear or play safe'
the other guy was too scared to run foul of the regs, remember the fiasco of shipping parts out and not using them last season.
Also Ron is responsible for Magnus, the facts are that since he has been there everything has changed, the other guy would probably have given

an extra day testing at Mags expense
sorry this is not coincidence, the team always had the potential and fast cars etc, it was just the weak and romantic leadership that always took the easy option and FAILED