The vast majority of the time, you'll have two edge pieces already in the E-layers and you just need to insert the last one. The only exception is right at the start of edge pairing with an absolutely minuscule chance of all 12 edge pieces in the E-layers being from different edges.During 5x5 edge pairing, should you look for all 3 edge pieces, insert them into the E-layer, then slice and join them up or insert the two you can see and as you're doing that lookahead and find the third one and then join it with the 1x2 already paired? I do it the second way, idk if it's too slow and inefficient
1. Two edge pieces inserted already, oriented correctly
If it's a wing and a midge, join and look ahead to inserting the missing wing piece.
If it's two wings, insert the missing wing piece then join. (Otherwise, you end up having to do a slice move to join.)
2. Two edge pieces inserted, but in opposite orientations
A few options:
(i) Choose a different edge to pair up.
(ii) Insert the missing edge piece in any orientation, then flip. (See case 3 below.)
(iii) Insert the missing edge piece while flipping another one. Try algs like R U' R2 U R or R U2 R2 U2 R.
Do any of these, then join.
3. Three edge pieces inserted in non-matching orientations
3.1. Wings match, but midge doesn't match the wings
Flip either the wings or the midge, then join.
3.2. Wings don't match
Join the matching wing and midge then flip that, or isolate the wing that doesn't match the midge and flip that.