This surprised me, I have several sets of Stormies... so I went searching the old posts on the forum last night.
Yes it looks like (in 2005) that SMs were originally mentioned as A4. However, it seems they moved to A2 quite quickly in Tim's mind and, after that, from the posts I saw, it sounds like A4 or A2 was an option on SM for a few years. By 2009 or so it looks like SM's were A2 as standard.
But I did see one post (from Tim) where he said they were A3... I suspect that might have been a typo, tho?
I got a distinct feeling that, early on, the Stormy Monday, Mule, and Riff Raff could all be given A2, A4, or A5 after consultation with customer. But quite quickly it became obvious that the SM wind suited the A2 best, Mule wind A4, and RR A5. But that sometimes a particular guitar or user requirement would make swapping the magnets a good idea (I did find, somewhere, Tim saying he didn't like A5/Mules at all himself but that some folks might want that harder sound).
There's an excellent thread regarding pickups for a 335 in 2008 (see here
https://forum.bareknucklepickups.co.uk/index.php?topic=13907.0) where the differences get discussed - and Tim explains his rationale behind A2/A4 recommendations for a SM, and why in this case he changed his mind to A4/Stormy for what the customer wanted.
All this has actually made me wonder about a SM set I bought second-hand a while back. It didn't seem as magical as the two other sets I'd bought new in the last 4 years or so. It was completely unused but was in the old style thick brown box (which I have many of myself!)...
These 2nd-hand SMs seemed to have a little more push to them, but the LP they went in had that vibe anyway. I've since put Old Guards in this LP which is a superb match (when I stop wondering what the pickups are in a guitar... it's "a superb match"!)
Meanwhile, these 2nd-hand SMs have gone in my Explorer. With this guitar I was ALWAYS wondering about the pickups every time I touched it... it's had the originals (500T and it's mate), Riff Raffs, MQs, 57 Classics and Classic/Classic+. None of it really made me forget about pickups... but the 57 classics did make me wonder about SMs. I was also considering maybe Mules one day. But as I don't play the Explorer much I wasn't in any rush...
So when the 2nd-hand SMs became spare, I just banged them in the Explorer... and WOW! "it's a superb match" too now.
I wonder whether these SMs have A4 magnets? From what I could discover last night, A4 in SM could move it between A4 Mule and A5 Riff Raff but with a slightly lower output. It'll lose some of the gorgeous sweet top-end clarity I love from A2 SMs, but very little. And it'll apparently tighten up the bass strings slightly (which, for me, doesn't usually need doing on the A2 SMs)....
Thinking about it now (at work) ... the Explorer could conceivably have benefited from both these changes without me realising it? I really wasn't expecting Stormies to work in the Explorer, not as well as they did...
I'll see if I can check the box tonight - might tell me what the magnets are (I don't think the original guarantee sheet, which would tell me, was in the box).