In one scene of the StrikerS manga, Subaru accidentally throws Teana over a wall during a team training exercise, and manages to jump over and catch her on the other side. Initially, this appeared to be simple Rule of Funny, but it was actually foreshadowing for the Robotic Reveal. Subaru also is able to read the class rankings from a distance where Teana is unable to do so, and in Episode 8, suggests that she can go for four or five days without sleep even while doing training.
Why does Revolver Knuckle have two spinning gears? Is it because Everything's Better with Spinning is being invoked twice? No, it's because they counter-rotate, so their torque cancels each other out and Subaru's aim with that arm isn't thrown off.
During the Final Battle, Scaglietti uses a glove that shoots out red strings, attempting to bind Fate. Fate cuts through them with ease, and then smacks Jail down. Proving that you can't even fight Fate WITH Fate.
In one episode, Subaru comments about the Yagami family being an invincible force should all six of them be on the battlefield. This is partly because of individual power level but also because the six of them fulfill the roles of a TSAB squad set up, more specifically...
Vita is the Front Attacker.
Signum and Zafira are the Wing Guards.
Shamal is obviously the Full Back.
Hayate with Rein make up the Center Guard.
Why are all of the Combat Cyborgs female? Jail intends to use them as surrogate mothers for clones of himself in case he dies. Consider that he may have done the same thing to Ginga.
When Vivio first transformed into her adult mode, why didn't she have the same look that the Saint Kaiser had even though she's the Saint Kaiser's clone? Two reasons; first, at that point in time, she has not seen nor she did not know what the Saint Kaiser looked like, thus had no info on how she should look. Second, even though she's been brainwashed, her subconscious dictated what appearance she should model herself after when she transforms, and the person having the most impression on her is Nanoha, thus explaining why her hair followed the same style as Nanoha's after she transformed and her barrier jacket carried elements similar to Nanoha's barrier jacket.
Speaking of the Cyborgs, Zest Curb-stomping Due may seem a bit odd, because Due, being out in the field for so long, should have at least some combat experience, right? It seems true, until you remember her occupation. Due is an assassin, not a warrior. She stays in the shadows and camouflages into society with her IS, and strikes when necessary before retreating. She wasn't designed for being on the battlefield, and the only weapon she has are her claws. Zest, however, has a spear, which beats the claw because of its long reach.
It is revealed that Subaru and Ginga are cyborgs Jail created and their mother happened to be on the team investigating Jail. What are the odds of that? However, with Jail actually working for High Command, it indicates it was probably no coincidence. He probably made the sisters for them, the pair were intended to be poster children and the High Command rigged things so that the team with Quint on it would be the one who find the girls. Result, The girls are in a military family and will most likely join up like their parents. And if/when the cyborgs are revealed, will be used as proof that the Cyborg Project has its benefits and is worthwhile.
There's only one problem with that theory, Jail didn't create them. Everything else is perfectly plausible.