As of Patch 4.5:
I equipped the javelin on SoTT bot. I noticed that once the bot is out of javelins, it will not ‘reload’ until the javelins are full (3/3), but will only ‘reload’ up to 1 javelin (1/3). I’ve not seen the bot reload up to 2/3 or 3/3 javelins.
This makes the bot less optimal and slower at having javelins ready for throwing since it only has 1 at a time and has to ‘reload’ after every time it throws a javelin.