I'm not getting into another argument about entails 🤣
Suffice it to say, there is no precedent for a queen and entails are of dubious legality, even if the political community were willing to accept a woman -- and I'm not at all convinced they were. Edward III's entail does not recognize the rights of daughters anyway.
The arrangement with Beatriz came before Richard took control of personal government, though, so we can't consider this an insight into Richard's thinking. Indeed, Jonathan Sumption writes in the third volume of his HYW series that it was John of Gaunt who impressed upon Richard's regency council the strategic importance of a Portuguese alliance. Gaunt believed such an alliance was necessary both for him personally (to keep his claim to the Castilian throne alive) and for England more generally.
Sumption writes that, at this time, that the lords had roughly split into two camps with regard to the war's prosecution:
- Those who advocated a "northern strategy" to attack France using the tactics that Edward III had deployed so successfully in the 40s and 50s, with Brittany providing a base from which to launch such attacks. (The focus of the "northern strategy" would shift to Flanders after the Flemish revolt.)
- Those who advocated a "southern strategy" and believed that England could not defeat France without first breaking the Franco-Castilian alliance. Castile's naval supremacy had devastated English shipping and trade and terrorized southern English coastal towns. England, however, had no base from which to launch a campaign into Castile after Juan I crushed Charles the Bad and took control of the Navarrese marches. And so, a Portuguese alliance was the only option for those lords who believed they needed to knock Castile out of the war before attacking France directly.
Gaunt and Langley were in the "southern strategy" camp. Woodstock was in the "northern strategy" camp. There was no real consensus among the lords generally, but Gaunt is credited with convincing the council to pursue a southern strategy in 1380, though Portugal's extreme ill-preparedness doomed the subsequent 1381-2 campaigns.