After watching the video of the first incident tried pressing spoiler push off in the sim. Quite possible that the sim doesn't actually simulate it very well but versus spoilers up it didn't make much difference. The wing can be held up effectively if it is well anticipated, rudder is also needed for this. What also made a fair bit of difference in the third incident, along with a well held wing, was the swift and prolonged use of full reverse once the wing went down which was probably the main reason it stayed on the runway for so long.
Just read from snowfalcon2:
In connection with the first incident in Aalborg, the captain in a press interview stated "he believed with 90% certainty the fault was an indication fault only". Evidently his experience of the "christmas tree" reputation of the Q400 (i.e. lots of more or less unfounded alarm indications) led him to believe the landing gear was most probably okay.
If this is the case it seems bizarre! Reports from the cabin state that the right MLG leg 'fell' from the nacelle with a loud bang (the actuator was no longer connected to it). The indication on the gear handle was 'not locked' and presumably the final check, the gear position indicator in the floor bay would have to have shown 2 out of 3 greens. That combination of events would lead most people to believe there was a 90% chance that the gear was unsafe. Far from a "christmas tree" reputation these are all sensible indications. Though hindsight is a wonderful 'skill' landing with a running engine on that side made a poor situation much worse, something which the unfortunate crews that followed did not repeat.