Tasers work in limited situations. Recovery time is fast and the pulse can be ignored by someone hyped up on adrenaline (or drugs but that's beside the point).
Now you're talking about a rework: a strong, fast zombie. Unless you got it cranked to incinerate flesh it will be ineffective to something which doesn't feel pain. You need to seriousky up the amperage for it to be effective (250kV is toward the high end of what a human carries on staticy days).
Let's look at the options again and start shoring up the plot holes. The enemy is a rework. A rework is reanimated dead people. They are capable of low cunning, have demonstrated an ability to use improvised tools and show an understanding for the cause/effect relatioship. The rework shows boundless strength and unyielding endurance coupled with the motor skills to run, jump, rend and pummel without requiring to rest. It will not flinch if it suddenly loses a limb or half of its body; once it is focused on a target it will keep going after it even into a situation which will negate it's existence. The only way known to end the animation of a rework is to cause significant trauma to the brain.
Let's look at the forces deployed against them and their handicaps.
Sci-Fi equipment is limited, possibly all designed and rushed into production when the threat was realized. Military construction bases were centralized in large cities; large cities were primary targets for the reworks and huge sources of zombie recruitment. Equipment, recruits, supplies, research, raw materials, resources - all were pooled from the productivity of cities. Specialized, cutting edge, equipment and weaponry requires much higher maintenance and specialized parts/consumables compared to low tech, ol' reliable gear. Let's face it, the military is scrounging and cannibalizing all they can get to keep things working without a majority of their factories supporting them. Ore processing, steel smelting, circuit board printing, ceramic backing, polymer weaving, precision molding, technician testing... these are all performed by factories in cities and the wage earning workers who make such marvels work. Those cities and their labor force were the first to fall.
Brings up point number two: population. Every person that dies becomes a rework unless there was critical damage to the brain pan. But there is also something which prevents new children being conceived. Reworks are continuously growimg stronger as the living population dwindles with each passing day; pretty grim stuff that. The problem is global, otherwise why would base, supply, recruitment and factory secors be vulnerable and subject to attack instead of being relocated to a country or continent not suffering from rework depredation? The dire straights are reflected by the contracting size of the defense forces and the rapid promotion of survivors to plug the gaps in the chain of command. The pitifully tiny force sent to deal a hammerblow to the Horde as a last hope to eventually triumph is an indication of how few of the living are left. Let's figure a hundred thousand world wide with 10K entrenched in North America. A couple hundred troops represents a considerable commitment for such a chancy plan, then.
Air support and air mobility is severely restricted. Performance aircraft (as all combat craft are) eat fuel at an alarming rate. I say alarming because how is a military base going to get enough to keep their planes flying if all the city refineries had thier employees turned into the undead? A base has only so much on hand before they run out. A single 10,000 gallon tanker truck may have enough fuel for ten combat fighters to each go up once. Each hour of 'up' time equates to multiple hours of 'down' time as maintenance needs to be preformed and these fickle machines to prevent catastrophic failure during the next flight (and any failure is a catastrophic failure when you're more than 20ft off the deck and going a minimum of 60MPH while riding a fuel tank strapped with high explosives!). Maintenance means parts, consumables, replacements and so on. For the showdown with the horde there were four aircraft assigned to the task, all transports.
Let us now take a look at ground forces in the Horde scenario.
Armor assets consisted of one squad of armored infantry and one light combat tank. Pitiful really, but the best that could be transported with the aerospace assets assigned. The last cough from a remaining industrial complex yielded all of this stuff. Armored vehicle are almost as bad as aircraft when it comes to supply requirements and are vulnerable in broken or urban terrain. Tank design was also geared towards a primary purpose of destroying opposing armor and fortifications with anti-infantry being a secondary consideration. As such, the main gun tends to be an unwieldly weapon against reworks. Ammunition for that gun will run out as well with little hope of maintaining a steady supply of replacements.
Infantry, the unarmored ground-pounders, use a lot of unsophisticated weaponry. In other words, their guns are known as being reliable fire arms and the ammunition can be scrounged from an abandoned sporting goods store, firing range or police station. Why no armor? Any armor which can be put on by hand can be taken off by hand and the reworks have hands. Maintaing a living soldier is easier than maintaining vehicles. It is also far easier to recruit replacements than to build more vehicles which still requires crews to operate and upkeep them. 'nuff said.
I was going to post something else but I've long since forgotten what it was.
"I don't know why, but watching 12-year old Japanese girls flinging their school uniforms at each other was wildly entertaining." - Azrael, Japanese Exchange Teacher