It's funny how Akechi had resentment, envy and love for Joker as well and wanted to stay dead. But Maruki thought "Two for the price of one" with both Sumire and Akechi.
Maruki never went into Goro's head as far as we know, at least not in depth. But he knows that Akira cares about Goro, and that this could be used as leverage (Maruki can say he didn't intend for it to be blackmail all he wants but WHAT ELSE WAS BRINGING AKECHI BACK FOR). Maruki holds a sort of respect for Akira and wanted him to come over to his side willingly. Goro came back not because Maruki thought it would be what's best for Goro, but because he knew that's what Akira wanted.















