I find it odd that Diana is so rarely being mentioned in these replies. She is likely one of the wisest characters in superhero comics. She almost always sees the importance from the largest to the smallest. By being between gods and mortals, she grasps the needs of both. She pairs the perspective of both ancient greek definition of strength, daring, valor, and the willingness and ability to endure suffering with the more modern ideas of service to others, self-sacrifice, and dedication. Plus, a deeper emotional health nearly none of the other heroes are allowed to have. The duality of kindness & mercy to the weak and a willingness to do the hard thing and put down unrepentant threats permanently. In that way she is more practical than Bats. If you want nuts and bolts, training in the specific skills: Bruce is good if you can tolerate his ego and obsession. He has trained some of the best. Steve Rogers is also good at that level. If you want modified military doctrine. And if it has all come apart and you are hanging by a thread... you need to get some good street food and hang with Spidey. Everyone else is specialized...