Re: mini buckers and p90s
They're interchangeable in a Les Paul because of the P90-sized mount the mini's come with, which are basically a P90 cover with the top pushed in. In a Tele, the Rat is right because it wouldn't come with the Les Paul mount so the rout under the pickguard might be smaller if the mini was stock on the Tele.
But you can always order a pickguard from LewGuitar or Warmoth or somebody that's cut for a P90 and have the body routed for it if necessary.