I would be rather miffed , if having recently applied and being told that only the A320 was available, and having signed up (complete with 5 years freeze) to find my buddy applying this week and getting offered B777 or even A380 !
Having had exactly this, being non rated with thousands of hours on Boeings. I would not have done it any other way. Getting in a month earlier rather then later would make a difference of at least 30 places on the seniority list at the moment! LH would probably have given a slightly easier lifestyle initially, but being already over 1/3 down the fleet seniority list I already have control about my working lines.