You're not the first to have thought of turning the Battle into a dedicated ground attack/tank buster aircraft, Shortround. As the discussion goes, with local air superiority it's a grand idea.
The RAF were hampered by their 'Bomber Barons', who tended to see that level bombing was an answer to everything. This all goes back to the Italian Douhet and Stanley Baldwin's "The bomber will always get through...", not to forget Trenchard's imposing figure. RAF policy pre WW2 stuck rigidly to the idea that the best form of defence was offence; i.e. more bombers. This meant dedicated ground attack aircraft and dive bombers did not enter service with the RAF for some time later. These were known as Army Co-operation and initially such units were equipped with the likes of Westland Lysanders. The dive bomber/close support Hawker Henley, which would have been an impressive machine, became a target tug and never got to prove itself in combat because of this narrow minded policy. This changed when chaps like Arthur Coningham appeared and changed RAF perceptions of close support in the North African desert. He became head of 2 TAF in France from 1944. Brilliant man.
Specification B.20/40 for a day bomber spec was also classified as a Close Army Support Bomber; the aircraft had to have a high speed, 280 mph at 5,000 ft using a Merlin, plus dive bombing and photo reconnaissance capability. Boulton Paul, Fairey, Hawker and Westland submitted proposals. Nothing happened. The Fairey design resembled a land based Barracuda.
In 1942 a spec was raised and issued to firms, but didn't receive a number, for a "highly manoeuvrable single-seat low attack aircraft for employment against military forces on the ground, aircraft, invasion craft and shipping." It's primary role was as a tank buster to replace the Hurricane IID armed with 2 x 40 mm cannon. Armament options for the new type was to be 3 x 40 mm, 2 x 40 mm plus 2 x 20 mm, 4 x 20 mm and six unguided rockets, or 2 x 20 mm and one Vickers 47 mm gun. Provision was also to be made for 2 x 500 lb bombs. Max speed was to be at least 280 mph at 3,000 ft. This spec saw responses from Armstrong Whitworth, Boulton Paul, Cunliffe-Owen, Martin Baker and Philips and Powis (Miles). Both AW, BP and Martin Baker submitted twin boom pushers, although BP submitted three designs, their P.100 was a pusher with swept main wing and canard foreplanes and end plate fins. They also submitted a short span cantilever reverse staggered biplane (!) design.
From all this in 1943 it was decided not to put a new ground attack aircraft in service and the Air Staff settled on the Hurricane IV and the addition of rockets to the Mosquito, Typhoon and Tempest; the advantages to these two latter types being that they could revert back to being fighters.