It shouldn't. Brokers are well accustomed to dealing with clients who have their own traders and engaging BestEx should be viewed as no different to employing your own trading team. Brokers are also accustomed to being remunerated by clients through a combination of execution brokerage and payments for research services. Critically, clients retain complete control over their brokerage allocation.
BestEx has no desire to interfere with the relationship between fund managers and brokers or to reduce the amount of brokerage which fund managers pay to their brokers.