I wonder why Jaguar use Ford engines? well Ford own Jaguar Cars and Jaguar Racing and also Cosworth Racing, so it would make sense to use your own engines.
Jordan also use Cosworth engines but badged as Ford`s, due to a marketing deal with Ford of Europe.
Minardi also use Cosworth engines but this is a deal only with Cosworth Racing.
Jaguar Cosworth CR-5 90deg V10
Jordan Ford Cosworth RS-1 V10 (last years CR-4 75 deg. V10)
Minardi Cosworth CR-3 75deg V10