They use different spell check engines, so likely not.
However, it seems that your dictionary includes some US English words (seems the OED allows -ize). You can replace the dictionary files (exact spelling is required), and you can even edit them (with a decent editor. I use Notepad++ for the purpose). Thus, you could DELETE from the file the “z” words that should be “s” words.
You can even create and download your own dictionary from SCOWL, at app.aspell.net/create. Choose the en_GB-ise option at the top, choose the word frequency you want it to contain, UNCHECK the “ize” spelling choice. You may or may not want to allow spelling variants, Hacker language, or diacritics. Download as hunspell dictionary.
Once you’ve downloaded it, unzip the file, open the folder, and change the names to en-GB.aff and en-GB.dic. Exactly those names (hardcoded into Scrivener). Copy them into C:\Program Files\Scrivener\hunspell\dicts\English-en-GB, overwriting the ones that were in there.
You could even load two dictionaries, by using a different country’s name. You could load the -ize English dictionary into, say, the Australian or Canadian dictionary space. Scrivener doesn’t really care which dictionary you put where, as long as they’re in Hunspell format and have the EXACT names that are supposed to be there. The license file for the dictionaries (the README file) should be included, but it doesn’t need an exact name; it just needs to be present (legal reasons).
Does that help?
And if you do this and run into trouble, don’t worry; the originals are easily recovered (delete the new dictionary files and re-download Scrivener’s dictionary).