I am now 81 followed basically the guide and here are my insides.
I dropped Gs and I am doing fine without him. However I bought the Kylo Ren command shuttle long time ago and used it as 5th 4* ship (now useless). Right now for anyone who needs and additional ds ship the Gauntlet might be a good package. After farming Lando I suggest to farm mods if you can 3* the 5 dot health challenge.
Regarding Lando and STH, both should reach at least gear 9. Both are needed in the credit heist and Lando is great in tank and get also.
Regarding Maul, Scimitar is a great ship and Zaul teams are easy to farm. What other high end team you are planning with if you drop him?