Not without the rest of the American army in support, because that replacement fuel and ammunition doesn't materialise in situ. Nor do you have any means of getting across a demolished bridge, or much chance of fending off an artillery barage or minefield - which may not kill you but will wreck a track quite happily - nor, unless you're bringing the GPS satellite network back with you, do you have a subtantially better idea of where you are - and certainly not where the enemy is - than they do you.
Very rarely is there a gap in technology which is unassailable until you bring 'magic' technology into the equation. A firing line of 88's to the front will probably not trouble Chobham armour (incidentally it's the antitank rounds, not the armour, with a uranium component) - with modern stuff being somewhere over twenty times as good as steel plate against antitank rounds - but a bunch of panzerfausts sneaking round the side will take out unarmoured tracks and possibly road wheels just the same as cold war Soviet RPGs and contemporary Iraqi EFP mines. An immobilised tank is not a good place to be.
The uranium bit was already taken care of for me

....
Thats just it, though. A single platoon of M1s wouldn't just magically go back in time to fight. If 'somehow' it was a force with 1940s technology against a force with modern technology, the modern force *would* have its GPS and refueling and joint force capabilities. F-22s and F-16s and F-15s would have total air superiority, B1Bs, B2s and F-117s would drop their weapons without being touched, while ground forces of Strykers, M1A2s and Bradleys destroyed everything in their path with A-10s, AC-130s and AH-64Ds providing close air support. It would all come in the same package. The devistating advantage of any one signle part of that package alone, though, shows just how much of a difference technology makes.
The 'magic' technology of today would bring the 1940s to its knees. GPS, night vision, lasers (as in guidence and range finding...) encryption and communication equipment (modern decryption would break *almost* anything they had avaliable to keep their actions secret)...
It would all be there. The opponent with the technology to field a space based heavy partical weapon has all the technology avaliable that led up to building that weapon.
Both were nasty in b5wars. The long recharge on the Warlock's heavy particle cannons usually meant after they fired they were brought off line and energy was shifted into sensors or additional thrust. The Sharlin with its jammer, high sensor value, long ranged guns, and grav engine, she could be quite the pain as well.
And again B5wars is game and therefore isn't 100% accurate(wouldn't be much of fun if EA couldn't even SHOOT at those Minbari ever for one thing).
It is *more* accurate than ACtA simply for its point system. B5W wasn't limited to 6 'priority' levels of strenght. While I don't remember the value, a Shadow vessel could cost 3k in points and be able to murder everything in a one on one situation, thus making the B5W ships 'closer' to their actual strenght, rather than fitting them into one of 6 nice levels.
Again, based off ACTA stats yes, but fitting background it seems unlikely. The Minbari where centuries ahead of anyone elses technology, and someone being able to match their primary heavy capital ship with the technical and technological resources of one world - no matter how motivated - is unlikely in the extreme. The Warlock is a bit of an exception as it has elements of Minbari and Shadow-derived technology in it, not just human hardware.
"Ship X is equivalent to ship Y" in ACTA tends to be a product of only having 6 levels for them to be at....
As to the Warlock vs. Sharlin, I had thought they were nearly on par with one another. Unlike the Omega, which was 'the last destroyer Earth would ever need' the Warlock *was* a truely devistating creation. In B5, Earth/Humans are such a great power and a great threat because they are the 'coming of age' race. While this is just back patting for the humans, they are remarked upon by the older races and feared because they are advancing at a paramount rate. Prior to the Earth Minbari war, they are at a level of technology behind the Narns, within the next couple decades they are nipping at the heels of one of the most powerful races in the galaxy, the Minbari.