Time for an another update, 2405.6
Two more bigger battles occured. My fleet of 35 ships against his ~20. No losses for our fleet, Joachim lost all ships. Another battle was my 31 vs his 20+ ships. I lost 4, Joachim all. This was enough to raise me to the first place in scores.
There's still one bigger battle upcoming, since Joachim has 30 ships in the same system I've the second fleet.