Multiple Employers Sponsoring H1-B

[goti66]

I am currently on H1-B Visa valid till Sept 2015. My current employer A has filed my extension application in June under normal processing. At the same time another prospective Employer B submitted my H1-B under premium processing, however at that time due to the PP being suspended it is still in the process and I didn't join them yet. Meanwhile I received another offer from Company C and I would like to join them instead of company B. My concern is as follows

 

Now with the lift on suspension of PP there is a fair chance that petition by employer B gets approved before Company C files one (under PP). If that happens would it effect in anyways chances of Company C's petition getting approved.  

 

I have informed about this situation to Company C, but their immigration specialist (not an attorney) thinks there is no issue at all. Would some one please advice if this is right. 

 

FYI: I do not want to reject company B's offer before joining company C.