TLDR: IMHO Simply the nature of how the Deed is obtained or made available, determines the relevant Pool and Class levels that influence it's abilities.
I haven't been able to find anything substantiated by devs however, with respect to everyone that has weighed in with much more experience than myself in the pathfinder world, I don't see how it can't mean the following:
Arcane Pool Points (APP) = Panache Pool Points (P3) (To include having "1" remaining)
The nerf is that any bonus you would get from Swashbuckler (SB) levels is negated (Com ref example: Prec Stk - you can take the deed and so long as you have 1 APP it would be "active" but the buff you gain is +0, so its useless) and you can't shallow dip to maintain an effectively constant buff where appropriate or (and i'm fairly confident the real intent) essentially "add" to your Pool account for those deeds. By obtaining the Deed in this manner it is as it's title suggests an Arcane Deed not a SB Deed and thus only APP apply to the usage of the deed.
Even the Evasion Deed, while still dope, gives you no defense from a Rouge's sneak attack, but still gives you the protection from all the other threats to negating your Dex to AC that UCD and +2 Atk Bon IUCD provide outside of the Rouge threat.
If you were to dip into SB your Panache is only available to be utilized for Deed's available to the SB Class only. (Ex: a LV 7 Mag/3 SB w/ Superior Feint Arc Deed; if you were out of APP as Mag but still had P3 as SB you couldn't utilize the P3 to use Sup Fei because your SB isn't LV 7, and conversely you couldn't take the Prec Stk w/ Arc Deed and utilize the 3 SB lvls to boost attack DMG.)
I do understand the confusion that the narrative creates (after reading the takes and it, many many times), I can't see any other way to take how it is specifically written coupled with how Flam Arc is written it seems they were just trying to (albeit in not the most concise manner) establish and emphasize that APP and P3 where not interchangeable and Mag and SB Lvls could not work in conjunction with one another in regards to Deeds.