''(e.g PC-9 (best aircraft for the job but to be built in Switzerland) vs Tucano (license built by Shorts of Belfast, a firm trying to survive in an unemployment blackspot at the time)''
The RAF PC9s - had they been ordered - would have been built by BAe at Brough. Belfast/Hull - both not doing well econimically and not much to chose between them. And as for the 'better aircraft', there wasn't much to chose between them. I've flown both and (in my opinion) the Tucano is slightly better on balance.