It has been awhile since I have done Gedcom imports. Do you still have access the list that showed you what you were importing? This may be the only source that has all these names in one location.
Now that you have imported them, you are going to have to look at them individually and search for matches. A more preferable approach for your next import is not to import them all at once. From that original list you can compare and merge before you import. No worries, starting with small imports like you did is the much approved approach, as you do more GEDCOMs you will be an expert soon enough.
When you set about merging them be sure that you are merging the newer profile into the older existing profile. Or more specifically, we like to have the lowest numbered Wikitree-ID be the final merged profile where all newer profiles are merged into the lowest number. An exception is if the newer profile has the correct Last Name at Birth or the one that has been agreed upon by profile managers and other interested parties. This is not so much an issue for immediate family members but becomes a big deal for historical and much older profiles with serveral profile managers.
Another reason to work in small batches.