My research on the common stats as they relate to winning.
Analysis about half way down, Drosphile doesn't agree. Also when interpreting stats I've chosen ones that allow me to talk about play styles, not necessarily the most win related stats (which amongst the basic stats is kills per minute I think).
There's loads of stuff you can't extract from logs, even with the advanced stats plugin present, mostly contextual data.
Looking for particular stats to apply to a class/role generally means you stereotype that class to a certain set of behaviours, which means that innovative or uncommon play styles will generally be penalised in any model that expects things to be different. For example it's common to attribute medic picks or forces to a roaming soldier, but Kalho for example played a highly atypical roamer role in the last ETF2L season which is highly effective within his team's setup. This lack of medic aggression from the roamer was counterbalanced by KnOxXx targeting the medic frequently.
As I illustrated in the article you linked to teams vary how they distribute this type of responsibility so it's very difficult to decide on a single statistical set for a player/role to achieve and say "this is what they should be doing and this stat shows they are or aren't doing it".