Of course they can pay lawyers however much they want to put their case forward and lawyers will act on their behalf but I doubt the lawyers who are as highly qualified as hours will have told them that this is a baseless smear campaign and that they'll look fucking ridiculous because there's zero chance of winning and infact be ridiculed because it's no more than a fishing expedition, for them then still to proceed with the case anyway.
Masters/PL are obviously keen enough to run with it, I'd be amazed if that's with the knowledge from their own well regarded solicitors that it's got no chance as you suggest.
There could be a myriad of reasons why the PL might want to pursue a case that they’ve been told they’ll find very difficult to win (if they have been told that).
a. If the case is deemed ‘weak‘ it might be felt that proceeding is ‘sending a message’ or acting as a deterrent.
b. Whilst they may not have all the evidence, they might well have assumed evidence would come to light, the longer things went on. Perhaps they thought they had a witness in the bag, or hoped they would get one, for example.
c. The PL may hope that they can weaken city’s defence, once the hearing starts or, by going with 115, they will get a lesser charge through?
d. The PL is, effectively a members club and the PL is accountable to its members. ‘Dropping’ this case might be perceived negatively, whilst proceeding may demonstrate its commitment to ‘go after everyone’.
Alternatively, they haven’t been told they can’t win because;
i. We’re banged to rights, the evidence they have is undeniable and we will be in the championship the season after next…..
ii. We have evidence they’ve not been privy to yet
iii. It’s not up to the lawyers to tell their client they can’t win and they’re just making the biggest pile of cash they can!
