At this point, you really can’t ignore marketing.
- Release DOTA 3 with a ton of marketing.
- Live action Dota 3 TV series
- A real Dota 3 Anime series
- Fix the Dota 3 Arcade (draws a lot of casuals in)
- Follow the Riot Games playbook in Korea but do it worldwide (the PBA Dota 2 league in the Philippines is a start)
- Copy the PUBG playbook with streamers when it first launched
Pick 1 hero and keep playing it. Since you have experience, it will be faster for you.