Many settings have made luck on the battlefield be tricky. Pray for your victory..
Every player has an arch enemy who they can not be friends with. They are forbidden to ally their arch enemies allies. If your arch enemy is no more, you have to choose a new one (has to be of similar size and power) from the other ones without an arch enemy.
A Kingdom of France vs F Kingdom of Great Britain
B Brandenburg-Prussia vs I Saxony-Poland
C Oman-Muscat vs D Kingdom of Portugal
E Kingdom of Spain vs L United Provinces
G Austria-Hungary vs O Ottoman Empire
H Shahdom of Iran vs P Mamluk Iraq
J Denmark-Norway vs K Swedish Empire
M Togukawa Shogunate vs U Joseon Korea
N Merina Madagascar vs S Sultanate of Morocco (they are the weakest slots anyway and need no additional challege)
Q Hotak Persia vs V Zungar Horde
R Russian Empire vs T Chinese Empire
W Mughal Empire vs X Marathi Empire
Having the War of Spanish Succession and Great Nordic War as first conflicts is advisable, but not recomended.