"You're good at being an Undine. It may take a while, but I think with your ability you can get business to go back to what it was before Alicia left eventually."

This is his true, unbiased opinion. Shirogane isn't one to let it slide when someone is not working to the best of their ability or if they're Kou, but even he is willing to admit when someone is doing a good job (it isn't enough for him that you're doing your best. As far as he's concerned, 'doing your best' is synonymous with 'doing what Shirogane thinks is your best'.)