for the standard run always go for 3 max evolved monster that is the easiest I think and core advice regardless of which monster you choose, in general having a strong well rounded damage dealer like a skimander/chikita/scutter is a good start, avoid haunted monster, tuskal is the worst monster in the game now I think
what did tuskal do to you? he may get instantly melted on the front lines because of his beserk ability but in the back hes a good boy and can easily deal 20 or 30 percent of my teams total damage dealt. I thought a haunted monster like gheist or woad would be able to top him regarding their ability to suck