Phineas and Ferb extras, recycled or crossover?

I keep seeing P&F extras milling about the background.
They fall into three distinct types as I see it.
1) Exactly as they appear in P&F.
2) As they appear in P&F but in different color clothes.
3) As they appear in P&F but with an entirely different color palette.
Some examples;

1) In "The Doctor Zone Files" there are several who appear exactly as they did in P&F standing in line outside the theater. The easiest to note is a guy in armor holding a staff who was in "Nerds Of A Feather" and "Drusslestienoween".

2)Pinhead Pierre Actress in different color clothes.

Pinhead Pierre actress in P&F

Pinhead Pierre Actress in Milo

3)Unnamed Mother and Daughter with a different color palatte.

Unnamed mother and daughter in P&F.

Unnamed mother and daughter in Milo.

And how about this near miss from P&F episode "Great Balls Of Water"

Slightly different hairstyle and softer lines.

Brigette in "Family Vacation"

So far I've noted a couple examples in the "Trivia" section for the specific episode where they appear. I have not included any examples of those with an entirely different color palette.
So I ask all who read this, are they noteworthy?
Should they each get a page and gallery?
Or, should they have a group page and gallery?
And perhaps most important of all, are they deliberate crossovers or just recycled extras, or some one case, and some the other?