I definitely think Shankland has still to prove himself in the top leagues. There are players that knock in goals for fun in the lower leagues then struggle in the top flight. Likewise, we have had guys like Craig Moore and Bob McHugh that couldn't cut it for us but had great success when they dropped down a level.
From what I've seen of Shankland, he doesn't contribute much more than goals. So if he's not scoring he doesn't offer much. That's unusual in the modern game - but goals are obviously a good quality to have as a striker, and when you score most weeks the other part of your game are not scrutinised.
When he was at Aberdeen he didn't manage a single goal in 17 appearances. While he was a younger player then, that will give a few managers second thoughts.
He has undoubted potential, but for me he is still untested at the top level. I didn't think he showed much against Hibs last week, but then he scored and helped them get a result. Will be very interested to see how he develops when he steps up to the next level.