Another difference is that, for the most part, Youjo Senki treats deaths a bit differently. If you notice, Tanya has never experienced major casualties. All of her close confidants and second-in-commands are all alive. Any death around her are either nameless mooks (even within her own unit), distant allies, or just straight up enemies. Every time any one of them is close to death, they somehow survive it.
This manga introduces you to characters and makes them interact with Touri JUST long enough for them to plant some seed of relationship/security and then puts their heads on gunpoint. You dont know when they will pull the trigger, but they WILL pull the trigger.
If anything, Groundless is a closer reading experience.