Практически все клиенты, с которыми

Практически все клиенты, с которыми ему пришлось иметь дело, оказывались в выигрышном положении.

Результаты (английский) 1:

Almost all of the clients with whom he had to deal was advantageous position.

Результаты (английский) 2:

Almost all customers, with whom he had to deal, turned out to be in pole position.

Результаты (английский) 3:

almost all clients, with whom he had to deal with, were in pole position.