The societal term yeoman generally means farmer. However, there is an elasticity on the term as a yeoman can be someone who farms on land he doesn't own or land that he does own. Kenelm Winslow owned Kerswell in 16th century England but was termed a yeoman. [See: “The `Loving Cosens:’ Herbert Pelham, Sir Arthur Hesilrige, and Gov. Edward Winslow” by Kenneth W. Kirkpatrick, NEHGR 154 (2000):78-108.] Above yeoman is gentleman or esquire. Then comes a knight, and finally you jump into the titled nobility. It is quite unlikely that a member of the nobility would marry into the yeoman class. It is also unlikely that a yeoman has noble connections in just one or two generations behind them.
The surname Dudley is famous and is interconnected with the great Tudor kings and queens of 16th century England. There is a chance that Gov. Thomas Dudley of Massachusetts descends from this Dudley family. However, the connection remains elusive and has never been fully proven. William Dudley of Guilford, Connecticut on the other hand, is clearly a yeoman as his father, grandfather, and great-grandfather all were. It is unlikely they have a connection to the baronial Dudley family. The commonalities are their origins in Surrey and the same surname.
It is perhaps easy for me to dismiss such a possibility since I have a slew of provable noble and royal descents, so I have no need to prove the Dudley connection. However, after study of this particular family and other such families, I'm fairly sure the two families were not connected.