(I'll ignore banzai, since that is a completely different tactical option.)
In most cases, HW is your chance, as an ASL-player, to make the same tactical mistakes that the untrained, incompetent and/or conservative officers of the Soviet union used (mostly early in the war).
For one thing, you have stand stacked for one player turn (meaning one enemy Prepfire). That is usually a very bad idea, unless the enemy has little FP or you have very good TEM.
Then you have to attack moving in stacks. This is a very bad idea. This nearly doubles the effective FP of the defending units. Note that Firelanes are extra effective vs HW. The boost in ML and no-PIN doesn't make up for this.
The extra MFs are often lost when you pay the highest cost of any unit in the HW. A single hedge can eat up 2 and sometimes 3 MF from those 8.
In most cases, running one unit at a time, avoiding resid and taking advantage of enemies cowering (and thus marked with final fire) are much more effective. Often, the potential threat from a stack with a leader hanging back and moving last, can make the enemy hold his fire and let the first units run freely.
There are a few situations where HW can be beneficial:
Through a huge graveyard, since that is perfect attack terrain.
When the enemy has very little FP (broken, smoked in, out of position) and you want to close with him ASAP.
When time is of the essence, you have a great superiority in numbers and can trade bodies for ground.
When you have to get through one enemy occupied hex to advance into another. This one is very subtle, but CAN be useful. I'll explain. It's the last turn, and the enemy have protected the Victory building with units all around, so you can't get into melee and make him non-GO. HW straight into his protective circle, hope something survives, focus all advancing FP on breaking the enemy in that hex (still no melee so only enemy is affected), he routs away (thus no longer locking you unit in CC), then advance into the VC building. Imporbable, but possible.
Janusz