I have faced this dilemma too. First I only have EB as my FF programme (back then when all *A had 100% mileage accural on all *A carriers). Then after I found out that wasn't the case anymore, then I signed up for SQ to get my 100% mileage accural. After that we did a couple of LH discount Y long hauls and found out that M&M gave more points for short haul segments then we all set up for M&M too.

The most recent flight with LX we found OZ gives the most points 70% - which means a lot since it was a long haul and there is another LX short haul coming up. So we are all now OZ members too. Plus OZ allows pooling and we have 5 years to struggle how to use the pts.

This is crazy but I'm too cheap to max. my points. Now I'm using points from my EB account and let it stay empty and I don't think I'll collect miles with EB because I don't fly with SAS.