I'm from Birmingham myself - originally, looong time ago
Never experienced Napalm Death there tho - thought it was more in Nam (ooh, bad joke)
Gotta give these guys a run. DM aint really my thing, but some folks consider NM, Opeth, and Scar Symmetry DM, and these groups definitely are my thing(s)
Btw I experienced Opeth yesterday eve on home turf in Malmö (KB). Woo-oo what a concert
To my mind, SS and Opeth are the groups I can think of closest to NM.
There are a lot of metal bands with guys jerkin off on their axes and drummers bangin themselves nuts on their double basses, but the difference between NM, SS and Opeth on the one side, and most other metal bands on the other, can be summed up in one word: Intelligence.
Go by the lyrics - the best indicator of quality in rock music