Grell's wife at the time, Sharon Wright, ghosted the scripting of most or all issues from #53 to 71.
https://www.cbr.com/comic-book-urban-legends-revealed-167/
Wow. I had no idea. Thanks for posting that. Reading the article, Grell says - "I was otherwise occupied with the Tarzan comic strip, Starslayer and creating Jon Sable. Something had to give and Sharon Wright just happened to be an enormously talented writer who thoroughly understood the character (something ensuing writers seemed to lack) and told a great story.
Boy, he's right about that. Warlord just wasn't the same after he and his wife stopped writing the series.