You say that, but it doesn't make it so. Singleton effectively recorded the same amount of rushing yardage as Allen this year with 44 less carries! Singleton had 1,015 yards on only 157 carries, a 6.5 ypc avg and 9 rushing TDs. Allen had 1,026 yards on 201 carries, a 5.1 ypc avg and 8 TDs.
Not only that, but Singleton has an additional 342 yards receiving on 39 receptions and 5 receiving TDs. Allen has only 147 receiving yards and 2 receiving TDs.
IOW, Singleton has a total of 1,357 offensive yards from the LOS and 14 TDs on 196 touches. Allen has a total of 1,173 offensive yards from the LOS on 218 touches and 10 TDs. (i.e., Singleton scores a TD every 14th time he touches the ball versus Allen's avg of a TD every 22nd time he touches the ball)
Your notion that Allen has put up the better numbers and has better "elusiveness" is laughably wrong and wholly contradicted by the actual numbers, especially Singleton's 6.5 ypc avg versus Allen's 5.1 ypc avg.