Mika, I appreciate you taking the time to express your concern and the reasons for it. However, this particular website was built this way for a specific purpose, and I can assure you seo-rankings are not what we're after (lol).
Thank you for your suggestion. Unfortunately, since the sites are already built, it would be more time-intensive to go back and add shortcodes. That's why I was hoping there was a plugin or script that would allow me to type in a string to search throughout the network, and replace it with another string that I specify.
Does anyone know if such a plugin or script exists?