Tanganga isn't a RB.
He can't play RB for 38 games a season and then we expect to challenge.
Its not signing a RB for the sake of it, its signing a RB because we really need quality in that position.
We need quality in a number of positions
I was very surprised Mourhinio named him as a RB as in youth circles he's always been a CB, bit having seen him playing as a RB, then whilst I'd prefer to bring in a top RB, if we had to compromise on one position as we couldn't fill all the positions with top players IMO Tanganga at RB would be one of the best compromises we could make