Wait, you complain about having no challenge in battle mode? I started playing on hard and let me tell there are some hair pulling inducing missions where plain aim/shoot/dodge tactics won't let you win by default especially with multiple types of tanks swarming at once. I can understand the boredom or frustration but I didn't really felt that, I just treated the battles as any other challenge in the game and fucking rocked them.
#teambatmobile
I think it mostly takes too long to ramp up into any challenge. It's basically just dodging lines for a large chunk of it before it adds more enemy wrinkles, but even then I didn't find much of it difficult until the final landmine side mission since it throws like 50 enemies at you, restricts movement options a lot, and I haven't upgraded armor much. It has moments of brilliance though.
I prefer the actual chasing mechanics. The APC takedowns were a ton of fun as you feel like you're on the very brink of total control as you weave between shots, knock enemies into walls and blow through a ton of the enviroment.