The M. crenata that you received was probably grown emersed, hence the height on it. Over time, it'll send out runners, but at a much shorter length.
I have some M. crenata that I received from lbsfarms that has a similar shape (four-leaf clover), but over time, it has grown to look like glosso. Leaf size is about double the size of glosso (height and leaf size).
For trimming, it's basically the same as glosso. Just snip the runners and plant them in smaller groups. Grows really quick this way.