Who is the better farmer?
The only measure that is meaningful is total resource yield. Therefore the better farmer is the one with the best gold grab, or heroic heist or whatever resource you decide is important. This is a game that rewards time spent in playing it.
Who is the more skilful attacker or who makes better use of their time in terms of hourly gold yields is a different matter. But farming prowess is mostly dependent on persistence and tenacity rather than skill. The best farmer would be a monomaniac
