Here's an instance of a $2$x$3$ sliding puzzle:
The $2$x$3$ sliding puzzle is just a smaller version of the well-known 15 puzzle. Many guides exist on solving the 15 puzzle, and there are strategies that work on any $n$ x $m$ puzzle, where $n \ge 3$ and $m \ge 3$, such as the one in this video. But these solutions I've found don't work in the cramped $2$x$3$ puzzle, or more generally, in a $2$x$m$ puzzle.
What strategies can be applied to solve these types of puzzles?