Dutchjock - I am not the slightest embarrassed to say when something is wrong at easyJet, but equally I am happy to say when something is right. Your tone suggests that easyJet has somehow behaved in an underhand way by offering commands at Madrid which you either take or leave. It strikes me that this is entirely reasonable and the choice is down to the SFO concerned who makes a decision in the light of his/her personal circumstances. If you turn it down then the offer goes to the next person on the list. I simply cannot see what is wrong with that.
We have become used to a period of unparalleled promotion opportunities at easyJet, whereby anyone with the minimum hours and appropriate sim grades gets a command course. Wonderful as that is, the situation should not be taken as the norm. Like every other company there will inevitably be times when such opportunities are not there. There are now only a certain number of commands available and it is reasonable for easyJet to promote people into slots at the locations where the vacancies exist. You are quite within your rights to turn down that opportunity and easyJet are then quite within their rights to approach the next person on the list. This process is completely transparent and everyone knows the deal. That is not blackmail by any stretch of the imagination.