^ Sorry to break it to you, but the 1700 kg estimate for Arctotherium is incomplete so we can't use that estimate since it's less reliable to use anyway since it's based off of a osteopathic ridden bone to inflate(or wank) estimates. So, Arctodus is bigger.
And yeah, Arctodus Simus would struggle against 2 Cave Ligers but it has been dealing with primitive humans, Smilodons, & even Columbian Mammoths(which are larger than African Elephants) before so it's endurance could turn in it's favor