Something like this- taking 20 hours to get to 100 proficiency (if playing random battles/quests) and then taking another 20 to get to 150 and then another 40 to get to 200 seems about right. 80 hours is at least a few years into a campaign and beyond where MOST players would ever invest into a single campaign and that is only proficiency with a single weapon and a few other skill and still another 80 hours away from MAX proficiency if 300 is the cap.
If you want to sit in the practice Arena for 5 hours of real-time straight and level right up to 150 proficiency- that should be up to the player. Doing that they aren't levelling anything else and theoretically got less return on their time from not travelling the map, gaining loot/money, etc.
Levelling up several weapons would take even longer and in the medieval era trained knights were capable of fighting with many weapons, they were not helpless if their poleaxe got broken and they dropped their sword, they could draw a dagger and wrestle or ward off a blow and pick up a fallen mace.
Also fighting in battles is only one aspect of the game... trading, building influence, running your clan, taking over gang territory/bandit hideouts, making friends and building an efficient army, etc are all different skills that take time to level as well. People who are asking for levelling a single skill to take 50 hours of real-time have no life outside the game obviously because to level the 4-8 skills you need for any character just to the minimum competency level to achieve things in-game would take 200+ hours.