Pilkington should be a priority even ahead of CMS in my view ,younger and with greater potential. But with his current injury its unlikely that we'd be able to sign him due to medicals and arranging insurance on the player as I understand it.
Smithies is certainly another with potential but he has been out of their team quite often this season, dropped or injured ?
Clarke would be a no from me. Reading their forum last night and there seemed to be a regular comment on him that L1 was probably his standard, infact one poster even suggested his aggression/enthusiasm often masked over his ability in the eyes of many of their fans ( rather as Prutton did with us).