I'm glad I stumbled across your message during a periodic search of the web as my old email account was hacked last October and I lost access to my notification service for genforum.
Oddly enough, in my continuing one-name study of the Ernle (and variants) family tree, I had reached the same conclusion about Michelgrove versus Michael Grove. Just which Michelgrove married an Ernle is not clear, unless one concludes that the connexion was via the widow, Joan (nee Best) of John Ernle, who later married a Michelgrove (as is revealed by TNA reference. Similarly Margaret Morley daughter of Nicholas Morley of Glynde and widow of Joan's son John Ernle married secondly John Lunsford (and possibly later a brother of Sir John Wood, sometime Speaker of the House of Commons).
The Ernle/Dudley connexion is also one I am exploring. It seems to predate Sir John ERNLE, the Chief Justice's early career involvement with the notorious Edmund Dudley.
Lots of loose ends still to tie up, but I am slowly getting a clearer picture of the family's earlier lineage prior to 1406. Whether I shall ever be able to extend it so that it connects with Luke de Ernele (ca 1166) who received the original 1/4 knight's fee less one virgate from his de Lancinges nephew remains to be seen!
Many thanks for your reply. Perhaps you can tell me the source of your interest in this research?
P.S. My typescript account of the family (begun 22 Aug. 2009) has now reached 468 pages (and growing).