Nobody will believe them!
No ;-) It doesn't work in this way ;-)
It works like "nobody is guilty if exist probability that he isn't guilty" ;-)
If someone puts that in an Ad then just ask the U21/NT coach
Disagree. Nobody is NT/U21 coach forever ;-) And there is no guarantee that U21/NT coach has good knowledge about skills of future NT/U21 players ;-) And please consider that our knowledge about engine still changes. 3 seasons ago manager who set guard without IS/ID/RB/SB in lineup as C was called fool ;-) Now the same maneuver is called like "great tactical choice" ;-)
Please imagine situation that somebody discovers another solution which works only with players who are considered as weak by all other managers ;-)
In Past people, who claimed that Earth moves around Sun, were burned at stake ;-)