One difficult issue would be the transfer of a modern BB (Bayern Class) to France, as the UK would not accept this thing. Bayern would go to the UK only, or the Versailles Treaty would not be supported by the UK. The Royal Navy simply would make the issue a breakingpoint, as the Bayern Class was Germany's most advanced design yet and the British badly wanted to test it and see how more advanced, (or maybe not) it was compared with their own designes of the period.
As for Battleships to be retained by Germany postwar: the Pre-Dreadnoughts too were rated as battleships, so the term battleships is a bit vague. If Dreadnoughts had been allowed to be maintained, supposed they were available still, the likelyhood was there the Allied Victors would decide to make additional limmitations as well, such as allowing size, or armament restrictions, or perhaps age.
Technically the Dreadnoughts of german origin were all aging rapidly, being overtaken in age by newer design ships and plans, especially of the new British and Japanese origin. Even Bayern was a 1912 design, based on the older König class, with a bigger gun. It was good at its time, but obsolete by modern standards, simmilarly as the Royal Sovereign class was. If germany would retain several of these, they would likely be more a burden than an asset for the development of a new navy. (They simply consumed too much of the personel and budget, otherwise going to new developments and technology.)
As in fightingpower, the German Dreadnoughts were all undergunned, compared to foreign designs of the period. 11 and 12 inch was the principle armament of all German Dreadnoughts, except the Bayern Class adn the not yet commissioned Mackensen class. 12 inch was seen as second rate for a first rate navy. (All other Navies settled already on 15, or 16 inch and even bigger (UK and Japan).) Only the second line navies of Italy, France and the remnants of Russia, continued to use 12 inch gunned ships. The Major Powers went bigger.
Concusion would be the following:
- Bayern and Baden do NOT go to France, as the UK would blockade this move. It wanted the ships for her own. (Made no difference to Germany by the way, but it was a breakingpoint in the Versailles Treaty. France at best could get lesser smaller ships, as France at the time barely could maintain a navy at all, due to the enormeous damage done in war on her industry and economy. Adding a bunch of large german ships would cause the French economy to go bankrupt even more than in the OTL, as these ships also would require maintenance and crewing.)
- Germany would not gain anything by keeping other dreadnoughts, other than prestige. In military terms, they had had their time and were rappidly becomming obsolete. Germany needed new designs of a much more advanced type. Problem was her poor and broken economy at the time directly following the Great War.
- At best the German Navy could for the moment maintain a limmited number of capital ships, either Dreadnought, or even pre-Dreadnought typs, just to keep personel familliar with capital ship operations, before starting to design and build new replacements.
So my guess is that Germany could maintain on paper more than in reality. The König Class would be maintained as a class, as well as the Kaiser Class, since these ships were quite well designed and shared many parts, making maintenance easier and allowing the overcomplete ships (2 in all, as there were 9 of these together) to be used for parts, saving a lot of money at the time. the other ships and classes would be offered for sale, to get some additional money. Only two would be maintained actively, due to shortages in personel and the rest would be placed into reserve, with one, or two acting as trainignships likely.