So you are now comparing Manny to Hernandez/Corica? Manny does his job well - he closes down players better than anyone in the team - but he is not a creative midfielder. Countless times he (or Lia for that matter) tried to make short passes in midfield and lost it. He does have a good cross on him though.
Totally depends how Ricki wants to play. With Lia and Manny being really good in closing down opposition space it allows Brown to charge up and get into the 6 yard box. They are both decent enough to maintain possession and switch play to our wings which is our strength. They also give an option for passes out from defence, generally speaking as soon as wet get possession Brown is getting forward and Manny/Lia are setting up play from midfield. It works for us. Say we get a really good AM it may mean that Brown gets benched as I rate Manny and Lia as more constructive midfielders and basically equally destructive midfielders as Brown, just not as good in the air or box.