It peaks around BR 7-8. It sounds like you want to win at top tier and solo queue correct?
Yeah
If you’re looking for a leo and enjoying top tier and winning just go play Italy. They have the 2A7HU with Gen 3 thermals. Just stay away from US and Germany as a solo queue player.
Lastly, if you’re going to commit don’t neglect CAS.
Thing about italy is you only get like 2 good tanks at top tier I think. France gets the leclerc and leopards. Correct me if im wrong tho.
I’ve got most of tanks you desire/consider.
UK is decent, end of the line if ahead of me but Challenger MK3 is super fun. Plenty of lineups too, one of the funniest 30mm SPAA and fun rats. Imo worth it, I decided to grind this out.
Germany - yeah you can go for 9.3 - 9.7 and for the top tier with time however as you said the teams are terrible and it’s exhausting playing alongside them. Great tanks overall.
France I can recommend up to 11.0, it’s fun TT overall with great 7.7. Leclercs are on big disadvantage, no armour whatsoever, weak round and huge FCS that disables armaments and can be taken by 50 cal AND anything explosive nearby like artillery strike. So either you are popping after a 1 shot or game becomes a repair simulator after every mosquito bite.
Sweden - great TT overall, pretty unique and fun to play. Top tier is promising, I’m currently researching the top tier STRVs
For a game style you described as preference, I would recommend finish the German TT and go with UK next or concurrently.
Imo, the TT basically drops off a cliff after 10.7. You go from decent, competitive MBTs, to some notably under powered MBTs and a non-existant line-up. Where you will mostly be usable 10.7 vehicles still (Ajax and Boxer especially, the ADATS is barely a 11.7 worthy SPAA either, and I think would be better at 11.0).
Whilst the CR2s are okay at 11.7, you shouldnt be seeing half of what you do in an uptier in their current state. The 12.7s ones should be 12.0.
Oh I really can’t tell yet, UK is obviously not meta but I believe it’s not total trash either. Currently I stopped rushing for top tier and started to enjoy fun lineups 8.7 and above.
All we discuss here must be taken in context that OP likes armored snipers, so firepower and strong turret. IMO UK would do better than France and it’s more interesting overall than Sweden.