In his discussion of the tomb monuments of the Cobham family, Nigel Saul talks about how the last generation of the Cobhams of Sterborough had to be content with their status as country gentry but their tomb monuments were splendid and hearkening back to the time where the family fortunes were on the rise in the reign of Edward III rather than reflecting the family's current circumstances.
Saul points to the enormous, "grandiose" joint monument of Reginald Cobham, 3rd Baron Cobham of Sterborough and Anne Bardolf and the tomb brass of Reginald's first wife, Eleanor Culpepper, which unusually features a banner alluding to the 1st Baron Cobham of Sterborough's rank as a knight banneret, as evidence for the family's attempt to clinging to the appearance of their former status. Reginald and Anne's effigy, Saul says, "more appropriate to someone of comital or baronial rank than a country knight".
But - Reginald wasn't "just" a country knight. His daughter, Eleanor, was married to Humphrey, Duke of Gloucester, making him father-in-law to one of the foremost men in England. What if these monuments are not gestures of a frantic groping back to the past glories but an attempt to emphasise the nobility of the family in view of Eleanor Cobham marrying "son, brother and uncle of kings", Humphrey, Duke of Gloucester? Saul also points to Reginald's founding of a college in Lingfield Church as part of his move to affirm his family's status. This occurred in 1431, the year when Eleanor seems to have gained significant public recognition as the Duchess of Gloucester.
On the other hand, Eleanor Culpepper died in November 1420 so, unless her brass wasn't commissioned for several years, it's unlikely the unusual design had much to do with her daughter's marriage to the Duke of Gloucester. Reginald's 1445 will left instructions for his monument and it seems likely it was built after his death in 1446, several years since Eleanor Cobham's downfall and her divorce from Gloucester. Regardless, it may have been an attempt to the assert the status he had held during her marriage - and there may have been hope that Eleanor's marriage to Gloucester would be restored.