Parivartana is the strongest among all the sambandhas. In any sambandha you need to know the friendship or enmity between the sambandha kartas. For Mesha Lagna Mars and Mercury are inimical. But for even sign lagnas this is not so, the Lagnesha and the 6th lord are friends. For Mesha the exchange of the Lagna and the 6th lord indicate life full of conflicts, fights, obstacles etc., but whether or not the native wins will depend on who among the 6th and the Lagna lords are stronger. And also other yogas in this regard. The parivartan yoga mean that you will eventually come out this situation as parivartana indicate reversals of the situation prevailing before. The dasa and transits can be used to time this. Or you can say that roughly 1st part of life is full of struggles and success comes in the later part!