I don't see where I said he swapped no 10 position with Kagawa in the Westbrom game. Didn't say Kagawa played in the no 10 role in that game either. The point is Kagawa was our best player in that game, yet was subbed out for Januzaj who had an average game.
People tends to forget Kagawa never had consistent game time at the start of the season. He might played 45-60 mins today and the week after, he would be on the bench even when he had a good game like he had in the Swansea game yet was benched for the Chelsea game. He wasn't even allowed to complete the whole 90 mins, even when he was playing well like the Westbrom and Westham games. It was only in the latter stage of last season Moyes started to play him consistently and he was our best player in that month.
What I don't get is why our fans keep saying he had a poor season when he only had 14 starts out of 38 games the team played last season. And out the 14 starts, he was played twice in a flat 2-man midfield which makes those games redundant by the way. And despite being shuffled around different position, he still had good performance against Westham, Westbrom, Newcastles, Norwich, Aston Villa and Swansea and was overall our best player in the UCL. So tell me, how he had a poor season?
If we compare his wing performance to Mata's wing performance for us, he's been better and even when his central role is compared to Mata's, he's also been better.
That aside, there's more to no 10 role than individual performance Januzaj tends to have in that role. It entails not only linking the midfield to attack but creating space through intelligent movement, awareness and good decision making when passing. That's why Lingard would always been better in that role than Januzaj. Just like Isco, him and Januzaj are all about making individual highlights but when it comes to knitting the play together as a team, they are found short no 10s.