jh, this post from another site suggests that the 900 and 400 of total and fighter losses respectively are if anything a considerable understatement for RAF losses in the Battle of France:-
Actually, there are several historians who point out the magnitude of the Luftwaffe's losses during the 1940 campaign in the west.
For example, E. R. Hooton, in Phoenix Triumphant p. 267-268 lists Luftwaffe losses as 1,428, 0f which 1,129 were lost due to enemy action. Hooton goes on to list 1,092 aircrew killed, 1,395 aircrew wounded, and 1,930 aircrew missing. Corresponding French losses were 574 a/c lost in the air (of which 174 were lost to Flak), 460 aircrew killed and another 120 taken prisoner. RAF losses were 959 aircraft (of which 477 were fighters and 381 bombers) and 912 aircrew killed or missing (of which 312 were pilots) and another 184 aircrew wounded.
This is from :-
https://forum.axishistory.com//viewtopic.php?t=111632
Other posts talk of 453 Hurricanes lost, the very great majority being on the ground.
You are right. Dowding's plea that his fighters be withdrawn from France meant that he could prevail, just, in the forthcoming Battle of Britain. A great commander and shabbily treated by the RAF, the Air Ministry, and his fellow RAF VSOs.