There were no Mauryas at that time it was the Nanda empire .
"Alexander intended to march on and cross the River Ganges toward further conquests, but his troops, worn out by the hard-fought battle with Porus (in which, according to Arrian, Alexander lost 1000 men), mutinied and refused to go further. Alexander tried to persuade his men to press on but, failing to win them over, finally assented to their wishes. He split his army in two, sending half back to Susa by sea under the command of Admiral Nearchus through the Persian Gulf, and marching the other half on through the Gedrosian Desert. "
Alexander the Great -- Ancient History Encyclopedia
"The army continued advancing as far as the river Hydaspes but at this point the Macedonians refused to go farther as reports were coming of far more larger and dangerous armies ahead equipped with many elephants and chariots. General Coenus spoke on army's behalf to the king. Reluctantly, Alexander agreed to stop here. Not too long afterwards Coenus died and the army buried him with the highest honors."
Alexander the Great (Alexander of Macedon) Biography
"He was anxious to press on farther, and he had advanced to the Hyphasis when his army mutinied, refusing to go farther in the tropical rain; they were weary in body and spirit, and Coenus, one of Alexander’s four chief marshals, acted as their spokesman. On finding the army adamant, Alexander agreed to turn back."
Alexander the Great (king of Macedonia) :: Invasion of India -- Encyclopedia Britannica
It seems the Madarsas need to update their syllabus
Seleucus had to deal with a much larger and powerful empire under the Mauryas which Alexander never had to face, no doubt Alexander's acheivements were remarkable but he barely managed to defeat a petty king like Porus.