How quickly do skeletons reassemble? Minutes, seconds, instantaneously? What are the ways to kill or incapacitate a skeleton?

Why no just crush their heads? would that work?

There are many questions similar to this, such as Behaviour of Roman army versus zombie horde. Could one of these questions just as easily answer your question?

Lots and lots of bones that need to be buried? Release the hounds!

What chemicals dissolve bone? Pick one of them I guess?

Roman army could mean all sorts of things. Rome existed for almost 1k years, ignoring the east. This is impossible to answer anyways. Warfare is too complex. It would depend on terrain, numbers, time to prepare and previous experience and much much more. Both sides would adapt and try to surprise the other. I think the best way to go for you would be learning about human vs human combat first (is it that different?) and then take an educated guess. You should be able to give a much more detailed description because you would've learned a lot. The more you know, the better your question

You haven't defined how your skeletons can be "killed".

@StarfishPrime : or otherwise "disabled".

I have edited it to make it more clear. Thank you!

Question looks good to me now

Thanks, can we bring it back from [on hold]?

Check out the scene in the world war z the book section were he talks about Roman's face zombies it's some good inspiration

Possible duplicate of What (modern) weapons could be used to destroy skeletal enemies as completely as possible?

@SZCZERZOKŁY : "What (modern) weapons", probably not a duplicate in most people's eyes then.

Comparing modern weapons to a Roman army is definitely not a duplicate.

@Pelinore And the answers are for not modern weapons. Aparts from nuclear bomb. It make no sense to duplicate answers just because the questions is "sligthly different".

@SZCZERZOKŁY : severed bits don't reattach either in that question

How strong are the bones hold together? Bones are quite light, they may have less force than a 8 years old. How does the skeletons percieve the word? May I confiscate all the heads and make the army turn into bones pile? If it's magically just a copy of the original, You just have human vs super-immortal-human. Where do one sign to become a super-skeleton? And slave that you don't need to feed.

They do not need their heads to work - do they need their heads to see?

Just do it Mr. Krabs style, with a swordfish skull

Wel obviously with sticks and stones.. Because sticks and stones may break my bones.. ;)

Related: Evil Dead

Does the skeleton army get horses? Do the skeletons retain other knowledge from when they were alive? Do they fight like romans or will they pull something sneaky like running around until the humans get exhausted?

good tactics and/or weapons to use : Testudo formation and acid, as mentioned in two separate answers in the 'dupe'. Acid is also one of the answers here.