Edit: so I finally got in, just extremely long loading times. Im running on an SSD with an R5 3600 16GB RAM...... weird, will continue to update if anything changes
To give another update on this. A lot of people that still experience crashes upon entering battle have this because of Horse Archers. So far T4 and T5 Khuzait Horse Archers are confirmed to be able to cause crashes. Leaving those troops in a city will allow you to fight if you have those with you.