Top talent is what a company wants in theory, but that isn't what happens at the job interview level. HR wants someone who won't complain and costs nothing, and the boss wants someone who won't threaten his job.
Ex-Servicemen are likely to challenge illegal or dangerous practices, and their leadership training and experience (rightly) makes an average to poor boss concerned for his/her own job.
Add in computerised keyword/profiling of CVs where many ex-servicemen get rejected for not having a 'standard' history, and the prospects for ex-Servicemen are not good.
Taking telecom companies as an example, are they full of top talent? Not at all; they are awful. Local Government, Banks too; the list is very long. To succeed, the company just has to be slightly less crap than the other companies. Their hires are nice, safe dull people whom they can work to death, and ex-Servicemen are not those.
In contrast, if one can get through the main man directly, and/or the job requires high levels of skill and dedication,then the ex-Serviceman has better than average prospects.