How to copy all files from under folders to one folder in Ubuntu?

Question

ubuntu

The point is exactly what. There is a folder, it has a lot of subfolders and files in them. You need to collect all the files on one level in another folder. Provided that if files with the same names come across, then look at the file size. If more - replace, if less - skip.
Found this command:
find ./images -type f -exec sh -c "mv {} ./images2/" \;
But it does not take into account the size of files with the same name. The Ubuntu console is not strong. Help me please.