1806: Austria, Prussia and Britain in France. The Napoleonic Wars became fierce and needed hard power.
1809: France (rich) and Britain (smooth landing) are not particularly good. Especially Austria mentioned above, although the generals talk endlessly.
18 15: It doesn't matter.
Ps: It is suggested to choose a country with geographical advantages in the anti-French alliance because there are factions of the British and Russian French empires behind you, except France. Did you see Osman arrive in Kiev? Italy occupied Vienna? Only France can beat London, Vienna and Berlin. ...