I wouldn't call Martial a flop, just over priced which is what happens when you have better than average 19 year olds - paying for future potential. Martial is not a good as his price tag suggests, but he is still a better than average strikers. I'd take him even over Vardy purely on an age basis even though as things stand the LCFC player is way way better. But I would not take him over Ighalo or Lukaku. Martial was brilliant last season in CL when Monacco dispatched Arsenal at the Emerates 3-1.
He scored some decent goals for Man U, maybe not enough but a better manager like Mourinho could get more out of him. He scored a great "Henry" type goal in one of his first games which was against Liverpool and for that reason I don't think Man U can call him a flop. Martial has had to change positions just so that LVG can accommodate his dutch love child Depay. With a decent Rooney replacement Martial can easily be a Theirry Henry/ Aguero type hybrid.
Plus Martial has given one of my favorite moments this season in the loss again St Bournemouth when De Gea failed to save an easy goal and Martial metaphorically kissed his teeth and glared at DeGea.
Going back to my original comment about Martial price tag this sort of thing is going to happen more and more : clubs like Man U being ripped off as they believe they are buying galacticos or future galacticos. I know Dele Alli plays in a different role, but Man U over looked him when they lost against MK Dons 4-0 because he was too cheap. There are really great players not just in championship, League 1, league 2 and non leagueUE (better than EPL or La Liga fare) but as Arsene Wenger said of £400k Mahrez the big clubs won't buy as they are too cheap and the fans demand big money galactico players even if the cheaper players might be better. I'd rather have Mahrez or Vardy than Depay and Benteke.
The reality is price tags and massive wages are just a guide and testament of great agents not an exact marker of quality, whether fans want to admit it or not , there are plenty of lower League players from teams such as Dulwich Hamlet, St Pauli, Nurnberg, Le Havre, Cleremont Le Foot, Forrest Green, Cheltenham etc who would be better than the likes of Falcao and Matteo Darmian. Cheap rag tag team Leicester City which, lets face it, is full of ex non leaguers, chancers and big club academy rejects, trounced Galactico Man City a few weeks back (Aguero, Toure and Sterling all played).
Speaking of Darmian I don't think he's set Man U alight defensively as a right back. He's getting away with being mediocre as defenders generally get less scrutiny. Injured left back Luke Shaw has been a much better full back. Italians have a reputation of being superb defenders, but barring his first few games he's been rather crap. Flop.
I am also underwhelmed by legend Schweinsteiger. Seems to care more about getting it on with Ana Ivonovic than playing well. Apart from lucky goals v Watford and Leicester he's done sweet FA to justify his wages other than living off his legend and sucking up to old boss LVG.