A user has made a tool available via the Mod section which analyzes the save game files and recovers information about wars. I used it on my old saves to reconstruct approximately when NGF/Germany formed.
Game 1 - Bohemia-Moravia: The AI should have had an easy time in this game since I weakened Austria and fought it for Slovakia
- 1873 - NGF formed.
- 1887 - Franco-Prussian War
- 1890 -Germany formed
Game 2 - Spain: I did not meddle in continental affairs for most of the game
- 1844 - Saxon-Saxon War, started by Saxony, finished by Prussia annexing them.
- 1859 - Prussian-Austrian Brother's War
- 1862 - Franco-Prussian War
- 1863 - AI forms NGF and then Germany immediately. If I recall correctly UK had sphered Denmark for awhile.
Game 3 - Russia: I did not ally with France and did not meddle in continental affairs
- 1857 - Franco-Prussian War
- 1864 - Prussian-Austria Brother's War
- 1870 - Again they do Prussia -> NGF -> Germany all at once.
I'm pretty sure the same thing happened with the UK.
Installed the Beta Patch
Game 4 - Italy
- There are no recorded wars for Prussia
- 1864 - Franco-Prussian War launched by the North German Federation
- 1875 - Germany formed
Game 5 - Philippines: This is the one I thought Prussia was surely going to lose.
- Again there are no recorded wars for Prussia, but this must be a bug in the tool as they lost a great deal of land.
- 1861 - Austrian-North German Brother's War - NGF and Ottomans vs Austria and France. NGF won.
- 1867 - Austrian-North German Brother's War - NGF alone against Austria and France. NGF won.
- 1873 - North German Liberation of Schlesien vs Austria. NGF won.
- 1874 - North German Liberation of French Rheinland vs France and Italy. NGF won.
- 1880 - Franco-Prussian War - NGF and Spain vs France and Austria. NGF won.
- 1880 - Germany forms.
Game 6 - UK: I was allied with NGF, but they never called me into the unification wars. I did not fight France, Russia, or Austria until after Germany formed.
- Several wars are listed for Prussia, but they're my conquests in India
- 1846 - NGF forms.
- 1863 - North German-Austrian Brothers War
- 1865 - Franco-Prussian War - (France + Russia) - won
- 1865 - Germany forms
So while those are rarely pre-1850s bad you may be on to something. It's definitely forming NGF faster in the beta patch. And there we have this:
- AI no longer obsessed with sphering the Kiel canal unless it has good reason to do so.
Why hello UK, not so interested in Denmark anymore are we?
Also notice that the VERY FASTEST time is when I played the UK. And I didn't influence any German minors or Denmark or anything. Hm...