4 Finger question

[Rebirth0]

I have this last question then I'm set for playing 4-finger.

When playing songs, does anybody switch their fingers to different keys during the song?

My Left Middle Finger, stays on the left arrow.
My Right Middle Finger, stays on the right arrow.
Normally, my Left Index Finger, is on the up arrow.
And, my Right Index Finger, is on the down arrow.

During songs, I switch my index fingers to the other key, should I be doing this?

Do any of you amazing 4 finger players do this? (Reach, Nima, justaguy, aperson)