Are there more risks than benefits associated with swapping guest posts with competitor blogs? Could you find that regular readers call less often, having been directed away from your blog to one that actually better meets their needs? Is this more likely if your blog has a bigger following than the other blog?
Overall the risk you are talking about is the one of having your own visitors stop visiting your blog after they discover the one of a “competitor” through a guest post you accepted. Is this a real risk? In my opinion, no, and for several reasons.
Will My Readers Leave If I Accept Guest Posts?