I see no one has reviewed the logs of the shaman in your guild. I am willing to go over one of the fights completely and give you and / or your shaman the exact reasoning as to why his healing may not be up to par. The reviews I do take me a very long time as I go very in depth and explain any faults / errors in the play-style and give explanations as to why you should play a certain way. I am only messaging you because I do not want to commit my time to a full overview of his game play if you do not think he is going to take it serious. The last log I looked at took me over 2 hours to fully review, but I don’t mind doing it if the person is actually willing to put in the work. (The first step to putting in the work is to come here and ask for help, which apparently he isn’t willing to do himself.) You say he is lazy and that scares me because restoration shaman is a very in depth class / spec that requires good reasoning / judgement on when to use certain abilities as well as tracking / maintaining up times on certain buffs / HoTs all while making sure a select few abilities are being used properly off cool down. If you would like, you can look at the last log review I did here: https://chainheal.com/forums/topic/moving-to-mythic-this-week/
Go ahead and link me his armory either through this post or a PM and I will take a glance at the logs and give you a few 5 minute tips that will increase his performance. Explain to him everything I have told you and if he seems serious enough and is willing to commit the time, I will go over everything with him in much finer detail.