I don't follow: If Eddy III (or equivalent) wasn't busy wasting resources in France, the English would still be itching for conquest. I'd imagine the most likely result would be English conquest of Scotland by 1400, and subsequent cultural integration. Without the distraction of Anjou, etc, Ireland would fall next. Thus something approximating the UK of GB & I, but in ~1450...
Simon
Except that you need to remember how conquest was achieved in this period.
To put it simply: a conquest of Scotland would result in numerous garrisons in Scotland to force the Scots to accept the English as their overlords.
The English Kings did not want the Scottish throne. They were quite happy to just insist on the Scots being their vassals, except that the Scots never stayed loyal to this idea. And after about 5 years usually those garrisons had been abandoned because of the cost or turfed out by the Scots. Maybe Edward would have launched a punitive expedition, but really with no appetite for English suzerainty it was surprisingly hard for the English to keep long-term control of Scotland. And I'm only thinking about how hard it is to keep control of the
lowlands... I'll point out something here: Edward III
did "conquer" Scotland. And like every other English expedition into Scotland (of which there were many) he failed to make it last.
An attack on the Irish similarly would achieve little. The Irish were too disparate, too prone to fight amongst themselves. It wouldn't actually be that hard for the English to attack Ireland and force the Irish to confer upon them the title of High King. What would be hard, like in Scotland, would be keeping it. The English only had a relatively worthless strip of land, Dublin excepting, in Edward's reign (and...at all, until the Irish clans were eventually broken down) which wouldn't serve well for a powerbase. And since Henry II's reign, half the Irish lords were Anglo-Irish, who had ancestors who had been English lords, and who were quite happy to live under total independence instead of bowing down to an invading Irish army. Even when some Irish did accept the English High King status (and it happened often enough) their rivals were then instantly galvanised into opposition to the English - and Irish lords
always had rivals. The entire island was one big mess of marriage alliances, secret truces and warring clans. If Edward comes along and dispossesses the opposing lords...then what? If he plants more Englishmen in their place, history already shows him that those men would be transformed by the social scene around them and in about a generation would be as disloyal and culturally Irish as the rest of the island. And socially Europe isn't ready (mainly meaning: Ireland's clan structure is too strong) for a single unified government to work, at all.