A fascist takeover of Ireland and an alliance with Hitler would actually redound to Britain's benefit. First, it would scare the Brits into rearming against Hitler more rapidly, second the Brits would go into Ireland and crush the fascist regime and afterwards would not give up its naval bases in southern and western Ireland. Hence, (a) more and earlier success for Britain against the U-boats, (b) less destruction of British merchant shipping, (c) better performance by British forces in the 1940 Battle of France, and (d) victory in the BOB with ease. Yes, Hitler advisers in Ireland would scare the *** out of Parliament and wake them up more effectively than a thousand Churchill speeches.