Ecth,
"Similarities between skills"
If you don't think about it too much, and just look at what you have, there are three "similarity" mechanics in each version of RM:
RMC: Stat Bonuses, Level Bonuses (RM2 "Similar Skills")
RMSS: Stat Bonuses, Professional Bonuses, Category Skill Ranks.
I t'werent saying that all was the same, but that those all end up serving the same purposes. . . My personal opinion is that "Similar Skills" is a total mess, a sloppy bit of logic that rapidly got out of control. Too much in the way of free lunch, and a lot of complexity, and also the chained logic was never checked, so you ended up with some nonsense like 8 ranks of Dance giving you 1 rank in Undead Lore.
Those logic chains bore a lot of abuse. . .and anyone can make a halfway decent argument to extending them further. "Shouldn't my 10 ranks in rapier give me some ranks in Dance, since both rely on timing, footwork, and balance?"
I'm happy enough to see that bogie mostly dead. . .only appearence SS has made in RMC so far is in weapons.
OTOH, the RMSS attempt to "fix" similar skills with those categories may have been a mistake. It's my opinion that actually killing that hydra was the right course to take. . .I suspect that any honest assessment of the categories in which you may purchase ranks can identify skills that seem absurd in association, as well as skill pairs seperated in different categories that seem like they should hold great similarity but flatly do not, since they're not in the same category.
The logic of say, picking up Rapier and Dance in the same training package, and paying for both, makes a lot more sense. . ."My rapier instructor made us take dance lessons to improve our footwork, balance and timing."
I suspect, the word "Similar" boils down to "But I want it for free!". . . .players love to argue how they should have free ranks in skill X because they have 20 ranks in skill Y. "It just makes sense that if I can do this, I should naturally have some bleed over of skill into that." . . .funny how that logic never came up when the player was spending DP. . .rather than pick up a rank of Dance here and there, they instead chose to double buy Rapier every level and pick up an extra rank in Body Development.
The whole basis and logic behind a third layer of "Similarity" beyond Stat bonuses and professional/level bonuses, in my mind, boils down to pure greed. If you want a broader character with a more diverse skill set, perhaps you should spend your DP that way.
BTW, since the rules on level bonuses are mostly optional in RMC, you can always choose the "Fixed Bonus" option if you dinna like the mechanics of the progressive method. (We tried to open the door to new ideas, especially keeping in mind RMSS). If you go with "Base PP", "Base HP", "RMFRP Friendly Skill Categories", "Fixed Bonuses" and "Non random SLA by Individual Spells" the first level characters are probably a bit better grounded than you'd think if your experience is only with RM2, not RMC. (In fact, those characters may look a lot like RMSS characters). . . . We tried to incorporate any good ideas from RMSS/FRP into the system, mostly as options. . .only a fool would think 20+ years didn't produce a lot of good ideas.