Well, I have been playing LoL too much to remember how creep pull in dota works but in LoL, minions are constantly being given orders, thus it doesn't matter that the attack command works until the target dies, because in less than 5 seconds the unit will be given a new order. Here's how it works:
Everytime a nearby unit is attacked, there is a priority check.
First, it checks if the new threat is higher than the creep's current target. Heres the order of priorities:
1. An enemy champion designated by a call for help from an allied champion.
2. An enemy minion designated by a call for help from an allied champion.
3. An enemy minion designated by a call for help from an allied minion.
4. An enemy turret designated by a call for help from an allied minion.
5. An enemy champion designated by a call for help from an allied minion.
6. The closest enemy minion.
7. The closest enemy champion.
For example, if a hero attacks a minion (#5), all nearby minions who are doing #6, 7, or nothing (simply walking around) will target the hero. But then if a minion allied to the hero attacks an enemy hero, that becomes priority #2, so all those minions who were targetting the first hero will try and kill the minion who's attacking their allied hero.
As for towers, the only place they appear is number 4. In other words, if there is a team 2 tower (priority #4) and a team 2 hero (priority #5) next to each other, no team 2 minions, the team 1 minions will target the tower, because if both the team 2 hero and tower target the team 1 minions, #4 has priority. But if there is a nearby team 1 hero and the team 2 hero decides to attack him (becomes priority #1), the team 1 minions will change target and priorize the team 2 hero.
One last thing, if a "threat" stops attacking its target for like 3 seconds, its priority will fall to 6 or 7 according to if its a champion or minion.
In short, what I just explained could be easily done, even with GUI (though differencing #6 and 7 may be hard, but then again you can just ignore those and keep only the 5 first priorities, as they are the most important)
I'm on a page about incorrect corrections, and spent the better part of like two hours trying to get someone to understand that -5^2 = -25, not 25, and then that post had comments get reposted because that group is self sustaining, and that person was in turn trying to explain what I just explained to them. And I'm taking that as a victory
I will be AFK for a couple of days you guys hold down the fort while I am gone. I will be checking in on my phone but that will severly limit me. Be back saturday!