EDDF (FRA) Approach to Rwys 25L/R - ATC vectoring question

[tva164]

The usual approach route for flights from south-west, west and north-west is to route them via RUDUS then on to waypoints DF029 through towards Metro or Gedern VORs and then vector aircraft into two near-right angled right turns towards the LLZ. Sometimes, aircraft from RUDUS are directed towards FFM VOR and depart it at 110 degs after which they are vectored at 070 degs then two left turns onto the LLZ. I am interested to know why they do this second approach as there is anyway enough traffic coming from south, east and south-east. Any clues ? Thanks.