Why when we are with rogue archer, the monsters do not directly attack the companion, but are constantly trying to attack the archer? It is as if they are attracted by the bow shots!
No it's a bit more complicated, it's about aggro. The enemy starts to attack someone who hits him, with rapid fire you hit more often than your companion so the enemy decides to attack you. I nearly died on Ironman run while trying the jesters bow with highest speed, all enemies only attacked me.
Ps: same for mage in dark Pitt, I learned it the hard way not to attack the enemies in there, I let my companion and summoner handle it, otherwise it's too easy to get the aggro and the enemies in pit are fricking fast. Happened more than once that I suddenly was alone against the spider while my companions are too far away to help fast.
Pps: you can also use that knowledge, it's really nice if you know how it works, that way you can let the enemy spin around with 2 meele. Once it attack your companion hit it with light weapon, it will turn around and your companion make flank damage, then just stop the attack it turns around again and you make flank damage. It's not easy but really funny sometimes