Maybe, but when one will say Germanic, i’m sure 90% of people with think of Germany rather than England.
Besides, England is Germanic mostly by language but ethnically it’s a mixture of Celtic, Roman and Germanic peoples…
English most Germanic settlement area is East Anglia where Saxons settled, rest of England is more or less Celtic. Scottish are by ethnic composition percentage wise (%) probably much more Germanic(Norse) than English are, yet they are considered Celtic due to Celtic language.