RMU established Combat Expertise Skills (Reverse Strike, Restricted Quarters, Mounted Combat, Multiple Attacks) that are "contra skills": rather than create bonuses for action resolution, they offset/reduce/eliminate the penalties for those types of actions. I'm not a fan for a couple of reasons:
1. They create a different mechanism than other skills.
2. They add to skill bloat.
3. It's premised on set penalties for various combat maneuvers.
So what we've done instead:
1. Establish weapon specific penalties for various combat maneuvers based on the weapon's size, speed, suitability etc. Granted it's arbitrary and could use some fine tuning, but adds a layer of weapon differentiation beyond to hit/damage ability. I posted up the weapon mod chart in this thread (bottom of page 3 or 4 I believe).
2. Created a use for a skills' # of ranks. So while each skill has a total bonus for resolution, the # of skill ranks is used for proficiency issues. In the case of a weapon, the # of skill ranks is used to lower the combat maneuver penalties and the fumble as well. This is basically the RMU shield skill model: the skill bonus is used for shield attacks and the # of skill ranks adds to DB.
I blogged about this last year:
http://www.rolemasterblog.com/rolemaster-skill-bonuses-skill-ranks/