In Dota Auto Chess there is no "one best strategy" that will always bring victory. Much depends on how other players act and which heroes are drawn. Nevertheless, from the very beginning of the game it is worth to have some initial plan and modify it in real time depending on the situation on the board. Below we have presented the combinations of heroes that create proven synergies and allow you to achieve good results.
Goblins and mechs - you have to start with something
Mechs are a great starter faction. From the very beginning you have access to three machines (Tinker, Clockwerk and Timbersaw), and to get the synergy that increases the health regeneration of all mechs just two of them will suffice. The priority should be Timbersaw, which also works well in the middle and even the final phase of the game. If you collect three goblins, you'll also get increased armor and regeneration for a random ally. The alternative to one of the three mechs is a very good Bounty Hunter.
Mechs lose their importance in the later stages of the game, so it's worth getting rid of them gradually (leave Timbersaw only). The alternative is to put everything on one card and try to create an army of 6 goblins. Thanks to their increased armor and life regeneration they can be a very annoying opponent. It is worth complementing the whole with the strongest units from other classes/races, e.g. Kunka and Dragon Knight, Lich and Enigma or Tidehunter and Medusa.
Army of warriors and knights
Warriors have a very good synergy to increase their armor and they work well both at the beginning and later stages of the game. It's also easy to improve these units if there aren't many players who invest in this class. From the very beginning you will have three level 1 warriors available (Axe, Juggernaut and Tiny), which will allow you to quickly gain a two-star pawn and orc synergy (Axe and Juggernaut). The Beastmaster also nicely completes the initial army (it is an orc).
Warriors' synergy improves with 6 and 9 pawns (of different types) and although the strategy for 9 heroes of the same class is not that bad, it is very difficult to achieve it. Other players will certainly pick up some champions for you.
A great alternative is a set of 6 warriors and 4 knights. The key here is Bat Rider, who together with Juggernaut ensures synergy of trolls (increasing attack speed of other trolls). Knights and their shields work well in the later phase of the game. In addition to the Bat Rider, Omni Knight (treatment), Dragon Knight and Luna (have area of effect attacks) will also be helpful. Thanks to them you will also gain the second level of knight synergy.