[quote=@babbysama]
I didn't see that the OOC was up until now for some reason! 

I'M HERE
[/quote]

Nice, was really disappointed when I noticed you weren't here (since I read through the interest check and you seemed really excited xP plus, having Persian characters makes it so much more interesting ;P)

[@Drunken Conquistador]

Hmm, one of the fortes of the Roman Empire was its phenomenal manpower. While it certainly was not the kind of Empire that just threw human waves at its enemies, it was certainly capable of doing so. As early as the Punic Wars, with Hannibal marauding through the Italian country-side, Rome could afford to lose 50,000 men in one battle (Battle of Cannae, with estimates as high 70-80,000), then punish those who lost against Hannibal by decimating them, and then raise another damn army to crush Hannibal.

Given that was 800 years ago in our current IC time, Roman manpower was something amazing even without the Western half - Byzantium was capable of calling up an army of 100,000-400,000 men at the Battle of Yarmouk (at a time when the Rashidun manpower was 70,000 at the max.) 
If we add the manpower pools of North Africa and the Western half of the empire, then the Empire at this point in time is a manpower behemoth. Meanwhile, the Rashidun had a manpower pool of some 41,000 in 634 AD.
While I understand that Rome had issues in the West, it is likely that it's manpower is great enough in West to maintain itself there, thus meaning that it was capable to fend off the Persians in the East simultaneously.

Thus looking at it from a completely military-power perspective, Rome seems to be an undeniable powerhouse. Of course, whether increased Roman manpower in this alt-timeline would be able to make up for the fact that the Rashidun were extremely skilled warriors and were adept at taking advantage of Roman weaknesses (that being the lack of mobile, light cavalry) and were also constantly defeating armies far superior to them in numbers anyway, remains to be seen I guess.

We also need to take into account what having control of the West really means: pretty much undisputed control over the Mediterranean. Being able to move armies swiftly by sea was vital to Roman supremacy, and I'd assume that if they've managed to hold onto the West, that Rome has managed to develop a rather formidable navy and is capable of landing armies wherever there is a threat in a reduced amount of time. There is also internal trade, no doubt a safer Mediterranean means increased internal trade, more revenues etc.
As a whole, whether Rome is embattled from all sides or not, there is no denying that it is in a a far better position than the Byzantines could ever be, militarily and economically.

While I'm very interested in Ancient History, I admit that my knowledge on it is not as great as later times (I much prefer my Ottomans, Safavids, Mamelukes, Englandss and HREs and France(s), even Spain and some Murica), so feel free to correct me if I've said something stupid xP