In the film "The Mummy" (and associated Animated Series), not only was the mummy in question a sorceror of immense power, he was built like The Rock. Mummified remains are extremely well preserved, much more than skeletons or other cadavers. The muscles would still be there. The only difference between a mummy and a zombie is the wrappings. Both possess immense strength, being undead and thus not actually feeling any pain when exerting force, and both have near unlimited stamina (the undead thing, again). There's nothing stopping this from being an apprentice of the Pharoah's army revived. Egyptian lore is rich with all kinds of fanciful magic, cults, and military institutions. Your fire hydrant example is simply idiotic nonsense. It shows you lack any knowledge of mythological folklore if you just assume undead mummy = frail, when every single legend puts any undead monster with more physicality than a meatless skeleton at near unstoppable levels of staying power.