Not sure I understand your question. I’d make the Explorer wing, just make a pocket to accept the arrow shaft. Try to keep the thickness of the wing as close to stock as you can.
If you would prefer an Armin wing, go head, they’re an excellent wing. I’d pick the size close to the stock wing.
Foam board is a wonderful material to work with, very forgiving. Flite Test planes are easy to modify to suit you needs. I wouldn’t double the size of the wing but +/- 10% will work just fine.
I’ve modified the wing of a FT3D, making the wing a bit bigger each time. My current wing is about 25% larger than stock, it’s now one of my favorite planes.
Let me know if I answer your question.