dvs7310 , that was a great synopsis of the options and the issues! ^
Something else to consider is what the accrued mileage would be used for - and how quickly.
If one only ever travels in J then *Gold may not be the most important consideration given one would get most of the status benefits anyway. On the other hand, if there is a propspect of quite a few *A flights in Y, then status for as long as possible would be the prize to go for. And if the aim is F redemption on LH, then Senator status with Miles & More should be the goal.
If one has no plans to redeem soon then crediting to a plan where it is easy to keep miles "alive" (Avianca's LifeMiles, for example) might make more sense than plans with hard expiry deadlines. Also, unless the FFP offers other convenient ways to earn miles (e.g. via credit cards etc.) there is always the danger of ending up with orphan miles that eventually expire. So plans that allow miles+cash redemptions might be a consideration.
Maybe the plan for usage is an edge case. For example, if it would be attractive to fly friends or family to Madagascar, then the ability to redeem awards on Airlink flights to TNR would be highly desirable. Only SA Voyager gives that option.
SA is also a partner of of some non *A airlines like Emirates and Etihad. No chance of earning status with them, and the earning rates aren't great. But again if they offer appealing redemption options, perhaps that might sway the argument.
None of this gets any closer to providing the OP with an answer. But I think it shows how many variables there are and hence the need to prioritise them for the individual. checkerboard, if you could indicate how important some of these considerations are to you personally, you might get more definitive answers.