The Hot Dog is a very good walker, but it is tricky to employ to the best of its abilities. The best possible situation could could have is to maneuver the Hot Dog so it is adjacent to an enemy squad, with an enemy walker just behind it. Ths way you can use the napalm thrower on both them in one go, along with your machine guns, very likely decimating everything around you.
However, most adversaries with a shred of caution will never allow such a situation to come up, and so you often end up risking your Hot Dog's neck trying to get the napalm into range, and more often than not the Hot Dog ends up killed before it can really do a lot of damage. Plus, if you manage to position yourself in order to put all your weapons to good use, but end up rolling poorly, you'll most likely find yourself surrounded by several very angry enemy units, and will not live to see another round.