Good find, but i hope you noticed panzergrenadiers are significantly more expensive, come later, you cant use them as your baseline infantry and have 4 models, making them vulnerable to things like, for example, 75mm sherman.
What do these things have to do with Tactical Movement and Panzerschrecks?
Having concerns about Panzerschrecks on Panzerfusiliers is fine, but we weren't talking about that.
As for shrecks performing badly while sprinting, it doesnt seem to be the case when you "a click" your pgrens blob in general direction of enemy tank. From what i saw its pretty common strategy in team games.
That's great when the enemy player is afk. If they are reversing their vehicles however, you'll find that the sprinting Panzerschrecks can not keep up and won't fire properly most of the time because by the time they are done turning around the vehicle will be out of range.