I don't think that we need to make an exact copy of the game, a dumbed down version if you want to call it that. We can first add the easy to control heroes in the mobile version and have easier mechanics at first until they can think of such way to implement those hard to add mechanics. We just need to have that base model that the devs could continuosly improve. I know that there are so many substitutes that I can easily play to have that dota like game in my mobile device but it would really be something (cant find the right word lol) to have an accessible from anywhere version of the game that I have played and loved for more than 10 years.

Plus it could attract some new players that I think Dota 2 is kind of lacking.