Agree with what GUWonder says, plus also status benefits are generally better on the home airlines. Having elite status in more than one alliance improves options available to me, but for some this may not make sense (eg if most travel is to & from places served mainly on the one alliance). Having elite status in more than one FFP within the same alliance is for arbitrage and extra status benefits in home airline.

Note LH is one of the easier programs to have dual status strategy on due to only needing to qualify every 2nd calendar year (or even every 3rd if you can qualify during Jan-Feb). If you qualify for SEN before the end of 2007 then that will last until end February 2010.