A strange thing

When I play Napoleon Total war with a Prussian Campigan I saw a diffrent thing. The Oldenburgs army has Line Infantery from Empire total war, and i found olso some cavallary form Empire Total War. I can show you some picture. Have you seen this strange thing in Napoleon total war.

Oldenburg in 1805 still used their uniforms from 1777.

But I think this was a mistake by the devs or a pun.

ok but why have they line infantery from Etw.

Not funny - lazy.

In any case the actual duchy of Oldenburg never had more than a single battalion of line infantry and a battalion of landwehr - both dressed in Prussian-style blue uniforms with red facings.

Once I saw ottoman cavalry from Etw

OLDenburg-a CA's excuse for their laziness. But actually, Oldenburg never have any decent units, so CA don't have any sources to make their own units.
But Oldenburg's lancers have rubbish skins, if you look close they don't have any lances.

ok