He was using combine arm force to attack you, so he is not a "nobraner" isn't he. Playing again an enemy who has a plan and know what he is doing, how do you expect to win ? A move in to him with you army ? I dont think so, you will need a higher lv of combined arm skill.
What other option do you have as ost? You don't as the only merit of the faction is combined arms. Just to re mind you; croc has high damage and roasts the At gun and infantry within the blink of an eye. It has high armor and high health, so it can soak the damage whilst it roasts the at guns and infantry. Then, your panther has low dps, so again you are out of luck. The brit also has infantry pounding you and at guns that don't get torched within seconds.
Your only option is adding in some stuka loiter, which basically shuts down the entire Crocodile strategy anyway lol. But still, I think the croc is in a good place right now. I don't see it that often to be honest, which surprises me.