Technically speaking a Titan is a tired old piece of junk, because guardians are zombies brought to life by Dinklebots everywhere. I bet if the travel ever saw Master Chief it'd go like " Holy crap, that guys a beast! I need him on my team! Chief come here and become a guardian! Weird the light!" Master Chief would probably accept just so he could become even more of a badass. Back to what you said, he is stronger than a titan, and can actually do everything a titan can, he can ground pound, and has bubble shields! He is also strong enough that at age 10 or something he killed 2 highly trained ODST soldiers in a wrestling match! He's also kinda young really, at only like 35 years old, and not aging when he was frozen. Really, he's like a Titan, if a Titan were smarter, faster, stronger, and had any real tactical skill. That is all in addition to MC being able to use any gun he picks up!