aptitude is well overrated, motivation is the key
Utter tosh.
So, pray, please explain what this aptitude is? Superior Kinetic/scan skills? We aren't talking FJ here....
The vast majority of entrants today (unlike perhaps twenty years ago, when they were run through a battery of largely meaningless mental/dexterity tests) have one criteria that needs to be met for entry. And that criteria is money in the bank to pay for the course. Nothing more, nothing less. There is no magic aptitude.... as has been stated most people who can get through a PPL SEP satisfactorily (nearly all reasonably intelligent people) can pass the ME, CPL and IR components (some easily, others with some pushing/extra training). After that the possible MCC and T/R are just extra cash. SOPS take care of those who might possibly waver later on the line, granted Base Training/Line training might reveal some weakness but these are usually rectified at this stage in the game.
At no stage do you have to demonstrate anything more than reasonable intelligence and the ability to manage co-ordination to that of a decent level and have the required maturity.