JWs experienced some of their strongest growth in the 1940s before shunning was mandatory. You don't need to shun to grow.
What you do need is a distinctive message and enthusiastic messengers. I think that a no-war, divine name, paradise earth-type message is more than distinctive and compelling enough. All the blood, 1914, creationism, anti-gay, anti-higher education, and so on are not assets to the religion, they are burdens.
The religions that grow best are distinctive but not shunning. The Seventh Day Adventists may be closest to the ideal. They are a bit more open than JWs, shun a bit less, allow a little more dissent and higher education. Yet they have distinctive things to say about Sabbath and about health. They don't have the balance perfect, but they are closer than JWs. And it shows because they experience continued growth and are financially strong. Their organisation and structure is much more efficient than JWs. But they still teach creationism for example, with a vengeance. So they are not perfect. They have some way to go as well. But they do allow more dissent and open discussion than JWs and that is absolutely crucial.