Cap would in no way beat Batman. We've been over this before. More experience. More knowledge of the martial arts. Much smarter. Master tactician. Cap would lose.
Batgirl is extremely special. She once sensed a sniper from a half-mile away. She even dodged four bullets at point blank range by only moving her neck. Elektra is out of league. Batgirl can "read" her movements. She'll know what Elektra will do before Elektra even thinks of what she'll do. Batgirl wins.
Captain America is arguably stronger than Batman. But Batman has mastered 127 martial arts. Captain America has only mastered akido, judo and several boxing styles. Captain America is nowhere near as experienced as Batman. Captain America was a wimp who got turned into a super-soldier with peak human abilities through a serum while Batman spent 15 to 20 years wandering the Earth EARNING his peak human abilities. Batman is a better fighter.
Cap is a very good leader but is by no means a better tactician like Batman. Read any JLA comic or Batman comic to see ample examples. He's DC's Doctor Doom.
Elektra cannot "read" movements like Batgirl. Body Movement is actually a language to Batgirl. She knows what you are saying even though she doesn't understand the words. She even pulled a random guy of the street to coerce him from commiting suicide. His body language said "I'm gonna kill myself". Elektra could never do that. Elektra spent several years under the hand. Batgirl was raised from birth with the world's deadilist assassins in training. No contest.
...Captain America is a master of all know martial arts in the Marvel Universe not like it maters though Shang Chi knows something like five and he is more skilled then Batman. The only help reading body language will do Batgirl is she will know Cap is about to feed it to her before he actually does.
Captain America is NOT a master of all known martial arts. Like I said he's mastered akido, judo and several boxing styles. However he does have knowledge of other martial arts. But he's never mastered them. When he got injected with the Super-Serum during WWII he was obviously trained. However he didn't learn everything because obviously it was wartime and the US really needed him to kick some a$$. He didn't get to spend 15-20 years like Batman to learn everything.
Shang Ci is better than Batman. But he has nothing to do with this argument.
One glance is all Batgirl needs. She'll know exactly how he fights, what is skills are and what he is going to do with one glance. Cap would be proverbially screwed.