Quote Originally Posted by abou
The losses at Magnesia were several times less than what Livy wrote. The Roman army was of a much larger size than what Livy stated and their losses much, much more than what Livy wrote. By all means, Antiochos could have continued the fighting and won (he never made the same mistake twice, btw, and Rome was full of terrible generals.). Rome was quite over extended too with fighting all over the Mediterranean. To add to this, Antiochos still had an alliance with the Galatians and Kappadokians - regions which Rome attacked in a dick move, and could have then only spurred them on to fight more against the invaders. As to why Antiochos didn't...
I can easily believe that roman loses were much bigger, but what reason is there to claim that losses of Antiochos were small?

Antiochos's army had only 19000 foot troops worth mentioning (phalangitai and galatians) and possibly up to 10000 silvershields (Bar-Kohwa's opinion)
The rest was composed of light armed levees, mostly useless as it was raining (the worst weather for composite bows).

Romans on the other hand had around 20000 heavy infantry, quite probably veterans of II Punic and II Macedonian wars.

If we add to this that Antiochos left wing was broken minutes after the battle started (own chariots and Roman/Pergamene cavalry charge) we see that the situation was not very good for Antiochos.

Phalanx and galatians were surounded by romans, inf and cav, and was massacred so we can assume 70% dead here. Another massacre was done in the camp, so I think we can easily assume 25000 dead plus 5000 trampled by elephants and people in retreat. Some were also taken prisoner.