Archers vs outsiders split from unfairly powerful monsters

[Beheld]

I have one comment/question...

What's this nonsense about "every encounter the Fighter will lose his permenancied buffs to dispel magic"?

Does every encounter at CR 20 even have Greater Dispel Magic and/or Disjunction?

Well, perhaps? CR 19-21 on the SRD has Pit Fiends, Balors, Titans, the Tarrasque, and 21 Dragons. The lowest Caster level Dragon casts as a Sorcerer of level 9, so they all have access to dispel magic as a potential spell known, and that's only one of the twenty one of them, most of them are CL 11-13.

Pit Fiends, Balors, and Titans all have Greater Dispel at will. So if you have to fight 10 encounters as a level 20 character, at least 9 of them (there is only one Tarrasque in the universe) have at least the potential to dispel.

The Pit Fiend's Caster Level is only 18, so he's only got a 35% chance of dispelling a CL-20 Permenancy. A Titan has a 45% chance, same with a Balor. A Grey Linnorm's (MM2) only got a 30% chance, and the other two in that book don't cast at all.

That would all be super meaningful if Permanency were cast at Caster level 20, but since that would cost a whole lot more money, and would break the magic 3k threshold of availability (how many level 20 wizards do you know who are waiting around to cast spells with an XP cost for you?) the fighter literally can't afford that. Instead, he has a Caster level 9 Permanency. Which the Pit Fiend beats on a 2. (Although actually, the permanency of Detect Magic can't be dispelled if cast at CL 20 by the Pit Fiend because "This application of permanency can be dispelled only by a caster of higher level than you were when you cast the spell." But also, see below where I introduce a second wrinkle.)

I could go on... but the point is that even all the single CR20 creatures don't have Greater Dispel... much less the CR19 & CR18 creatures that you'll encounter in small groups.

Again, lots of CR 18s and 19s also have the ability to dispel Caster Level 9 permanencies. The Dragons with CL 9 probably could (there's a lot of ways for Dragon to have a much higher CL) but a Nightcrawler also has Greater Dispel Magic at will. So we still haven't found a single non Tarrasque monster ECL 18 or higher in the SRD that can't dispel this Caster level 9 Permanency.

But the main point is that these Permanencies are Caster Level 9, and therefore easy to dispel, even before we get into the possibly lower caster level of the attached spell. (By RAW, a targeted dispel rolls once against the permanency, and once against the spell made permanent, and the permanency isn't actually worth anything after the detect magic ends.)

And all that is assuming you don't find a Wizard who has some CL bonuses to do the Permenancy!

If you want to explain where you find the uncommonly available spell caster who is willing to do this for you. But if the answer is "I have my own pet Wizard buddy who does what I want" I have to question why this counts.