It also makes some sense that you'd begin to get the feel for your opponent's skill level
More like three seconds. An opponents stance speaks tons in the first half second. The next half second reveals if you interpreted poorly as you wade in for the first, and hopefully successful, attack.
I find describing the defensive and offensive abilities of a foe relative to the PC's a good approach. A 110 OB/45DB PC faces off against an 80 OB/80DB foe, I will describe the NPC as having solid footwork, he obviously knows his away around his weapon and his defense is solid, it will be difficult to penetrate. The PC can act accordingly. But when the 192 OB/70DB fighter runs into the room on the 17th freaking round of combat, I will describe the NPC as well trained and quick but lacking the talent to be a serious threat, his defense is full of holes...which with a 192 OB, it IS.
When I plan encounters one thing always on my mind is combined OB/DB of foes and how well they need to roll to score crits. I aim for descent rolls of 70 to 90 delivering A-C crits, with A-B preferable. A few A crits dont kill, but they only kill on a very high roll (typically 100). My goal is to injure, maim, hurt, use up those healing supplies and lower pp totals. I learned long ago a player feels fear as soon as you the GM picks up the dice. Any blow will increase the fear. The A and B crits simply increase odds I wont kill them in a battle short of the sories climax (were often the bad guy is considerably betterthan the PC's in offensive ability).
There is a handy table in RMCI that records the results needed for first critical achieved on average for the RAW weapons and spell tables. I have expanded this table for every weapon, spell and SM attack table. Knowing what weapons are weaker against certain AT's allows judicious application, even providing the players an edge, or depriving them of an edge. The scimitar is the worst sword against higher AT but fairly effective against light and no armors. Equip your NPCs with scimitars against your chain and plate fighters and you provide them 20 points of hidden DB. Not that they know that, which is perfect. You can even up the NPC OB a bit and make em afraid, the entire time knowing the danger has not actually been increased, but the players will talk long into the night about that Hobgoblin Guard with the 105 OB and high init bonuses.
Having lethality with A crits maintains a sense of dread and fear that helps make good drama. It also re-enforces the moral that fights are dangerous and should be avoided. I think the 1-5% chance of lethal blows is a good thing and removing it would alter RM flavor in a negative way.