If you are saying there is very little difference between the skill list on the back cover of Character Law 1, and the skill list as is appears in RMC2 - you never played a character under both systems.
The difference in the game after the revised Character Law and Campaign Law and after RMC1 and RMC2 is HUGE.
Spell Law and Arm's Law/Claw Law did not change -- and the base underlying mechanics are the same. But everything else did. The Skill list expands by ... a factor of 20+. There is also Creatures and Treasure in RM2 which did not even exist in RM 1st Ed. The number of base classes mushrooms - all the Spell Lists in RMC1 and RMC2 are added. Background options in RMC1 are added which dramatically change character generation. It's a HUGE difference.
RMC1 and RMC2, taken together, are about 10 times the page count of the original Character Law.
Ok, I am going to have to clarify what I was. I am really thinking of the underlying mechanics. Other wise DD 1 to 3 would not count.
And yes I did play RM 1 and 2 using both sets of books with interchangeably. RMSS was a major change but not 1 to 2. 2nd Edition used the same Character Law as 1st edition and came out in 84. Are you sure you are not confusing RMSS (1995) or 1/2 with the expanded skill list from RMC 2?