I would fix this even before the call to submit method. The aim of the submit method is to submit jobs not to fix the LFN of the log file. 
In addtion I would fix the resolvePFNs to get as parameters 1 site or a list of siltes  +1 LFN or a list of LFNs. Also here, the resolvePFNs should not fix a giving LFN as we are doing for LFNs of the log files.