Is it possible, with PODs at any preferable time, to have the Romans conquer all land (Parhia/Sassanid Empire) up to the river Indus?
I doubt Crassus would have much succes, he was never all that impressive of a commander, whatever opportunities that may present themselves Crassus would likely either missuse them or fail to act. If Armenia got in the mix, roman cassualties would likely be lighter, but Armenia would be much easier to conquer for the Parthians after having bested their armies on the battlefield - i do however think Crassus would have the sense to withdraw after several defeats. However that is not an option for Armenia.According to Wikipedia, Crassus had the following troops at his disposal at Carrhae:
36,000–43,000 men
"With the aid of Hellenic settlements in Syria and the support of about 6,000 cavalry from Artavasdes, the Armenian king, Crassus marched on Parthia. Artavasdes advised him to take a route through Armenia to avoid the desert and offered him reinforcements of a further 10,000 cavalry and 30,000 infantry.[18]
- 28,000–35,000 legionaries
- 4,000 cavalry
- 4,000 light infantry
Crassus refused the offer /.../."
Would the additional 40,000 troops and the Armeninan route have turned the defeat into a victory?
If so, a second POD could be for Julius Caesar to live longer and go through with his plans to invade Parthia, building on the victory of Crassus.