For my part I'm not especially bothered about whether or not England has Dukes at the start. Yes, it's ahistoric, and it'd be nice to have a bit more historical accuracy, but I'm not bothered enough to argue about it, just so long as Earls are in.
Barons would be nice too, though I'm not sure how the existence of baronies would/could/should be modeled. If we find each county divided into rapes/ridings/lathes etc. then we could find ourselves with a stupid number of provinces (and dynasties), horrendous lag and near-constant revolt, so it's something PI will have to think long and hard about if they want to get it right.
And where does it stop? Do the rapes then get divided into hundreds, hundreds into tithingss, and tithingss into hides? At any rate, the term 'Baron' didn't officially exist in England in 1066 AFAIK. The structure, to my knowledge, was
KING > EARL > TENANT IN CHIEF > SHIRE REEVE > INSIGNIFICANT PEOPLE
but by the end of the timeline was more like
KING > DUKE > EARL > BARON > etc.
Which raises the issue of ranks not being constant, not only across cultures and realms, but also across the timespan of the game, which means that either PI are going to have to really work magic, or else whatever they decide to compromise with will be inaccurate anyway
