There aren't actually all that many players who have made the move from SPL to EPL.
Still, the point about having to go back a few decades is a fair one, you spoil it by saying they would struggle to avoid relegation as every single one of those players was playing top half football during...
Heres a decent XI of players who moved from the SPL to EPL
Fraser Forster
Nathan Patterson, David Weir, Virgil van Dijk, Andy Robertson
Stiliyan Petrov, Victor Wanyama, John McGinn
Paolo di Canio, Mark Viduka, Steven Fletcher
Not a bad team that.
Undav was barely given a chance, was only given 6 starts in the premier league - and he scored 4 goals in those 6 matches. He might have been good enough with more opportunity