For the specific three species, you mention, re-growing from the "low-cut" stem is defenitely possible, but unfortunately not allways very reliable, depending very much on general health of the plant and tank environment. Often only a single, new shoot will appear- sometimes none at all.
Working with these three species, I therefore allways combine letting the "low-cut" stems stay and re-planting several of the off-cut tops inbetween (remember to remove lowest leaves of re-planted tops, so no leaves end under gravel/soil). The tops will defenitely root and grow and any new shooys from "low-cut" stems will add to density of the plant group.
Rot. mac. amd Myr. tub. is much more willing to branch from un-cut stem, then is Rot. wall. by the way.
When you later do general trimming of group of these plants, you should use same method, to ensure vitality in group.