On Saturday, a goal apiece from Hernandez and Arnautovic helped the Hammers beat Watford 2-0 at the London Stadium.
Chicharito struck his third goal in four Premier League matches, while Arnautovic - who had been out with a hamstring injury - has scored seven goals in his last 11 games in all competitions.
"Marko is an unbelievable, all-around player and it gives you a lot of confidence when you play up front with a player like him," the Mexico international told Sky Sports News.
"We have a good understanding with each other and both of us scored. That's a good thing for a striker.
"Not only did we score, but the whole team ran with high intensity and we showed that we wanted the three points.
"Three points are three points whoever they come against, and we need to keep going day-by-day and game-by-game because every game is going to be a final."
West Ham remain 12th in the table but have extended their gap to the bottom three to five points.