Lot's of Video's and Thoma's the Tank Engines MerchandiseReally? This lovely message was seen today in a newsagent's window.
Just pluralising something does not need an apostrophe.
Add as many numbers of things as you like, you do not need to apostracise it.
Sophie's Choice: The choice belonging to Sophie.
Sophies' Choice: Lots of Sophies making a choice, possibly a cafe?
Thomas the Tank Engine's Track: The track belongs to Thomas
Thomas the Tank Engines Track: Some weird activity that lots of Thomases do when they get together.