IMHO that standard is too high. I think we should instead focus on words that have apparent Germanic transmission, i.e., they got into English via Germanic speech. Otherwise, you're dismissing words that apparently come from a Germanic source, just because they haven't changed much in the Germanic family or the rest of IE over time.
Then we get:
- good => Germanic
- new => Germanic (O.E. neowe, A.S. niwe, Proto-Germanic *newjaz)
- first => Germanic
- last => Germanic
- long => Germanic (O.E. lang, Proto-Germanic *langgaz)
- great => Germanic (O.E. great, Proto-Western-Germanic *grautaz)
- little => Germanic
- own => Germanic
- other => Germanic (O.E oþer, Proto-Germanic *antharaz)
- old => Germanic
- right => Germanic
- big => Germanic (originated in a Germanic context possibly from Norse bugge)
- high => Germanic (O.E. heh, A.S. heah, Proto-Germanic *haukhaz)
- different => Latin
- small => Germanic
- large => Latin
- next => Germanic
- early => Germanic
- young => Germanic
- important => Latin
- few => Germanic (O.E. feawe, Proto-Germanic *faw-)
- public => Latin
- bad => Germanic (originated in a Germanic context possibly from O.E. bæddel)
- same => Germanic
- able => Latin
I get 20/25.