Less toxic? Probably not. This type of game by design creates a more toxic environment than any other. It's got little to nothing to do with how ranked works.
Compared to other types of games, top-down MOBAs are a very niche case where:
- we aren't using WASD to move
- we have lots of downtime walking to lane/respawning
- we have an /all chat
- we rely heavily on allies' performance, and
- the game is PvP
It's the absolute worst environment for player interaction. Other types of games have one or two of those things, but it takes all 5 to make an environment that breeds such behavior so well. For comparison:
Solo games, obviously, have no one to talk to, no allies, and aren't PvP. So there's no one to be toxic to.
Co-op PvE games, whether or not they use WASD or have downtime, don't have the same competitive edge that PvP games do. And often times you can simply have someone join you whether or not they know how to play, because you can carry a mission yourself. That's the sort of game where veteran players will just give away stuff that's really good for a newbie but is a weaker version of something they have.
Other competitive PvP team games, like CSGO or R6 Siege, don't have the downtime or free keyboard to type out when you're angry. Granted, games like that have much more voiced toxicity, 'cause, well, League only lets you voice with friends.
One other MOBA is pretty free of the trappings in League, because it uses WASD to move and has no /all chat. So you don't have the downtime while walking to lane since you can't walk and type. So the best way to be toxic in Smite is to use the announcer command to say, "You rock! Cancel that!"
Now, about your suggestion, it wouldn't even do anything positive for the ranking system. Because enemies have respawn timers and minions spawn at a fixed rate. So your ally getting 400 farm means you can't possibly get anywhere near that. And an ally who can kill the enemies 1 on 1 before you even get near means you can't get the kill or an assist for it. So it'd just become a game of screwing over your allies to get your own performance to look better.
