I have never gambled. However, I know how the gambling industry works. Read up on it.
If you setting a line, your main goal is to attract people to place a bet on that line. Plus you want to attract those who are
WILLING to place a bet and
HAVE the money. You don't care who wins or loses. You make money when many people bet a lot of amount.
BD supporters are not willing to place a bet (religious reasons). BD supporters don't have the money to out bet the English.
So the line should be set to attract the English/British or potential gamblers to place a bet. 3-0 England line (that is what the English and others are thinking because of their outstanding current form and finds (Stokes -Woakes) plus a weaker BD side with no Fizz) is expected. Thus not many people would bet for England. Now if the line is 2-1 BD, English and others would say England is better than that so I would put some money in that. Now the better would make money with each and every bet placed by people.
Dave is a smart line setter.