Louis XXIV
Le Roi Soleil
The Order and Autocracy combos seem backwards. Nazi Germany had gangbuster science but wasn't known for its diplomacy. Soviet Russia, space race notwithstanding (which was their Germans vs. our Germans) was technologically quite backward, but was all about playing diplomatic games in the international community.
I think everybody can think of reasons why the "missing" victory condition could apply to that ideology.
Nazi Germany used threat of force to encourage a broad coalition to invade the Soviet Union - Bulgaria, Hungary, Romania, etc. all fought with the Nazis inside Russia. I think that's what Gunboat Diplomacy is essentially representing and why Autocracy has some advantages for diplomacy.
That being said, COMINTERN and United Front are both good ideas for diplomatic advantages for Order. Maybe someone will come up with a mod that gives all of them advantages for each condition. It'll be more boring but feel more realistic, I suppose.
FWIW, although they call it a Science victory, it is essentially a Space Race victory, so I wouldn't say "space race notwithstanding."