Are the free generals actually good and end-game material? Because that'd actually be insane if some of them were
Everyone except Grant, Selivanov, Esperey and Cadorna.
Infantry:
Nicholas I has great stats, mostly great skills (Tunnel is a good skill, however it has bad flexibility because Grenadiers are now exclusive to France and Russia) and can reach Emperor. A much better Infantry general than Grant.
Carol I has good skills and stats. Even though he starts as a Prince, a good general that can reach Emperor is always nice.
Cavalry:
Sheridan has good skills, stats and can reach Emperor.
Jackson has mostly very good skills and stats. He can also reach Emperor. One of the best cavalry generals.
Moltke the Elder starts with impressive stats (30% total damage, and he is a Viscount) and has mostly good skills. Compensates the fact that he can only reach Duke.
Todorov has mostly good skills. Even though he is another general that can only reach Duke, he starts as a Knight which means that he can gain a big amount of battle ability.
Navy:
Farragut, despite being able to only reach Duke, has good stats and great skills.
Cobanli has good skills and stats despite being only able to reach Marquess.
de Robeck is only a good Duke, but again has good skills and stats.
Max Loof also has good skills and stats despite being only a Duke.