Yes, they should not be like that. That impairs the functioning of the charging system. Google "gluing magnets to flywheel" for a variety of suggestions on doing that if you don't want to spring for a replacement flywheel...
And if that oil isn't from penetrating fluid to get the flywheel off, you might consider replacing the crankshaft seal.
And if that oil isn't from penetrating fluid to get the flywheel off, you might consider replacing the crankshaft seal.