Warham, regarding Cpt.Serviolas's high tonnage...
I've check his log a bit and it seems that his bunker time skips are really low (5-6 days, should be 28 days with twos). Add to that arcade realism settings and the result is high tonnage score.
Anyway, no big deal in my opinion, the man is playing in his own style with most of the war days spent out at see and not in the bar with whores (450 days at sea until mid 1941-respect

)...