Paulus Magintie:

Spartans arn't made they are trained. they have been around a few years before contact harvest (2525) they gain ranks after each mission and earn the highest rank available cheif went straight to master cheif petty officer which is equivilent to gunner sargent or somthing im not to sure on ranks (corret me guys if im worng) to them and earned every medal in the UNSC

Except the prisoner of war

They not attack defence units they are super soldiers used in most missions wether it is doing an all out assault or defending critical positions and if your gonna contradict me for what i just said then that makes all units attack and defend units :/

 Dude you make not sense

Anyway the monitor 343 gulity spark AKA lightbulb used protocal to fight the covies not the humans until cortana took the index now spark was'nt destroyed unil the end of the human covenant war so there would've been no reason to attempt to make a replica
Besides the covenant cant make a moniotr that can control halos systems setinels or even an AI smart enough to think on its own and learn they can only make Dumb AIs while cortana is a smart AI thats why cortanna could delete there AI. but still both sides dont have the knowledge or technology to make something so advance

The conanant don't make A.I.'s because they believe only the forerunners should make them, though they do have the tech. Also it was mentioned earlier that Spark was rampant, which is not true, he was a "perfect A.I." and by perfect i mean he was fully functional like Cortana, but does not have the 7 years operational limit like other A.I.'s he also would not be imprinted off a brain like the smart A.I.'s .he went "crazy" because he only has 2 purposes the primary is to protect his ring, and the secondary is assist other forerunners/reclaimer when installation 04 was rebuilt he had a purpose to follow again and could not let that purpose be destroyed again