if a the monster attacks heroes that have the same initiative, roll a die to determine which one takes the damage, rather than we pick who gets to take the damage. )
Or at least give it some suspense. just an idea.
I can see some merit to the idea at high levels (3-4) but in general terrible idea. There is enough randomness in the game, and it's tactically important to have this freedom. Else you would die too often. When normally your healer could save you, while you are shielding the healer, in your version the healer would simply die.
Really, leave that to the creator and playtester: I'm confident such variants have been tried and rejected.
You should get the pnp version ($5) and try out for yourself.