Zaha didn't play for the winners of the Championship. Palace finished 5th. I don't see how that goes against Zaha anyway. The Championship in general is a very open and competitive league with no real consistency. Zaha was one of the key players in getting them into the playoffs.
Why doesn't it really matter if Zaha was one of the best players in the league? (Football league young player of the year 11/12, Football league team of the year 12/13). He was recognised for his ability and potential at that level, and it wasn't just based on goals and assists (which no footballer should be judged purely on anyway) but his overall play, which was impressive. I don't see why those accolades should just be disregarded.
Stats don't really paint the full picture for either player either. Zaha's performance levels dropped quite severely during the transfer window when big clubs were sniffing around him, though he gradually picked up as the season went on. A lot of players suffer on the pitch when their future is up in the air, though he did well to improve that towards the end of the season. Lingard scored 6 goals for Birmingham, though 4 of them came in one game - which is an excellent feat itself, even if it was against an embarrassingly poor Sheffield Wednesday side at the time. So like Zaha, he went a lot of games without goals.
Whenever I watched Zaha play for Palace, he seemed to carve out an impressive amount of chances, getting behind the defence, playing the right ball into the box, but unfortunately they didn't always result in goals, but stats obviously don't record that. I'm not doubting Lingard is a good player, but I don't think he has looked as dangerous as Zaha has overall.
Both are good players, but I don't see Lingard as the better player just now. Perhaps he might go on to be a better player, especially if the stuff about Zaha being a waster are true. Personally, I'd be surprised if either of them have long term futures at United, especially considering the attacking players we have now.