The scale of bomber coverage an Indian Ocean campaign would need

How many early Lancasters would have been needed to matter in the Atlantic and Indian Ocean?

He sketches about eight wings in total, roughly 300 aircraft, with around four wings for Indian Ocean coverage.

Meaningful coverage would require a wing in Canada, one in Iceland, two around Scotland and Northern Ireland, and roughly four more across the Indian Ocean. That produces an illustrative total near eight wings and about 300 Lancasters. Canadian, British, and possibly Indian air forces could share the basing burden. The estimate is deliberately broad, but it gives the industrial scale of maritime air warfare: even hundreds of heavy aircraft could remain a small fraction of a bomber establishment planning raids measured in the thousands.