I don't think we have 12 players competing for 4 positions - that's a bit of a simplistic way of looking at it
Currently as it stands
Wide players / Wingers - Lennon / Chadli / Lamela / Townsend - that is 2 per wing which is more than acceptable
Defensive Midfielders - Sandro / Capoue - 2
Central midfielders - Dembele / Bentaleb / Eriksen, Paulinho - 4
Attacking Mids - Sigurdsson / Holtby - 2
Bearing in mind we might see Timmy's 4-5-1 more often than not later in the season - that leaves a healthy competition of 2 per position, inclduig EL games - completely reasonable number for a team challenging for a strong finish - all top teams have strong cover in just about every position, not sure why we need to compromise.
In any case - seeing all of the above fit and available at the same time would be highly unlikely - as what this season has taught us so far