Just to clear some misunderstandings:
1. As far as I know, for quant positions, the reputations of Columbia MFE and MIT MFin have roughly no difference in HK. If you target IBD and S&T, MIT will be absolutely better but this is not the case for quant positions.
2. The class size of Columbia MFE and MIT MFin are roughly the same according to QuantNet information. I heard that for the Fall 2021 entering class of MIT MFin, a majority (70-80%) of students were interested in quant tracks. So the class size should not be a huge difference.
3. It is true that Columbia's career service is incomparable to other tier1 MFE programs, but it is being improved. The career support of MIT MFin is also not that competitive either according to comments in QuantNet.
Back to your question, I totally agree that for quant finance career, Columbia MFE is more rigorous. So your choice should depend on whether you want the bright title of MIT, or the solid preparation in Fin Eng by attending Columbia.