I think it would be tricky to cut the STÄLL shoe storage unit into half and get it working properly. It just wouldn’t be worth the trouble.
Cutting down the 3-compartment tall STÄLL (removing the top 1/3 section) would be a better bet. For that, you’ll just need to cut down the two long sides and reattach the top piece.
If it is a matter of space, the 2-door BISSA is a smaller shoe rack that may be what you’re looking for. Just cut out the notch for the handles and cover with some edge banding to replicate the look on the STÄLL shoe cabinet.