What will people learn from the GFS II fighting?

This post is a connected followup to Boss/Worthy/Fodder ranking the GFS II guys.
Meta-gamey concerns I have as a GM

The Master/Gith almost solo'd the whole group, even with them using potions and Great Haste. This was for a few reasons.

One, he was using buffs, too. Missile Shield for one, some spellstones and potions graciously donated by previous delvers for another.

Second, the players didn't have their cleric with them, which meant the Master/Gith wasn't trying to undo Curse over and over, and the PCs - used to constant and immediate healing - had the same problem the Master/Gith did, which was, no one to heal injuries.

Third, he was legitimately boss-level - some very potent advantages, some magical gear, excellent armor, and spells. His skills were also high - experienced PC level skills.

He lost anyway, for a few reasons.

His disadvantages dictated a way to fight and a way to handle the threats of the PC. He couldn't just do the most efficient thing in the moment, although he generally had a lot of good options.

The PCs outnumbered him in the end, and it didn't all that much to take out what forces he could muster to help him. With no one to watch his back, the PCs kept after him tightly, forcing him to hit and move and hit and move until he made a mistake (disads are disadvantageous, it happens) and was taken down.
But still, he managed to kill one PC, and knock out two others, before going down.

My game concern is that the players will react by thinking, well, if DX 25 (!) and Skill 25-28 wasn't enough to overwhelm this guy without taking losses, we need to be at least skill 25-28 before DX potions. Slams didn't work well on this guy because he was very strong for his slight build, so people might start thinking, we also need more strength on everyone. You know, what if - just what if - everyone else got killed and one of the PCs had to solo one of these guys. Better for all concerned that the PC has more skill, more ST, and more DX than this guy, right?

That will work.

But then it means instead of a foe like this being interesting, a foe like this has to become the new baseline. Otherwise, any foe with attacks that work on mundane lines - roll to hit, apply defenses, apply DR on a hit, inflict injury - will likely be total wastes of time. Crit-fishing will still work just fine, but their defenses won't when a skill-30 guy succeeds by 20 on average and their defenses don't even reach 20. In fact, defenses in the mid-teens are rare on foes. 12-13 are more common, and 10-12 more common, still. In an attempt to make a boss (one on many a match for PCs) like this more like a worthy-level foe (one on one a match for a PC), it came mean just about total overkill against everything else. When that happens, as a GM, I really have no choice but to make high skill and high defenses and Feints less or not at all relevant. More trick monsters, less like-on-like challenges for the PCs. This is the Invulnerability Trap I have discussed before.

So I am considering skill-capping. Sure, that means more people pushing to DX 20, but they're going to do that anyway. But DX+10 as a skill cap is on my mind.

Might be seen as unfair, because I won't promise you'll never find a skill-25 guy with DX 14 on the other side, but it might stop people from pouring more and more and more points into a single axis of power and groaning when the adventures present broader axes of demand.


Another possible issue is, we can't do it without (blank.) That might be (our cleric), or (another wizard), or (buff spells on everyone), or (a fountain of DX and ST and Speed potions). It's a dangerous road ahead, for sure, but it's going to be tough if no one is willing to go without a massive amount of buffs. It will become a logistical hurdle to delving in new areas. This I am less concerned by. If PCs achieve overkill by spending thousands of dollars per delver per fight, it'll naturally become a bleed for excess cash. It's annoying as a GM when it means you can't really gauge the strength of the PCs - are they ST 15-20 or more like 21-25 due to potions, or DX 20+ due to potions, or immune to missile fire due to Missile Shield, or are they not? But it's not a problem.

My final concern is the caution trap, which is the two above plus more. If this was so hard here, what about a couple levels down . . . is it worse? Yes. Will that mean people insist on doing to this level what they did to every level above? That is to say, loot it down to the door hinges and not move on until they've "cleared" the level to maximize their point value before taking a further risk? They may. I sincerely hope this teaches them that a forward risk is the way to go - the big loot, the big fun fights, the cool exploration and insight into Felltower's internal logic as rewards for pushing the envelope a bit.

We will see.