Worth remembering as well that the Franco-Russian alliance only worked because of Napoleon's victory in 1813-14, and the subsequent deposition of the Romanovs - I highly doubt a non-constitutional monarchy would have been able to work with France quite as well as it did until the Great Kurdish Crisis in 1902 and the Eastern War in 1906. I definitely agree that France is pretty much essential in any hegemonic alliance, though - France has been the most powerful nation in Europe since the 1400s at least, and just has too much of an entrenched advantage over other European powers to slip away from that.The thing was that the Franco-Russian alliance was so overwhelmingly powerful because of their size and because they didn't have any real conflicting interests. I don't see anything matching them in ATL. The Alliance OTL maintained hegemony for a century, but competing interests(like France backing China with Russia backing Japan) let to the Franco-Russian split, causing Russia to court Prussia and Britain and France to ally with Austria. Again, I don't see any alliance not including the French Empire being powerful enough to maintain a century long hegemony. We'd see more wars for sure.