You can't properly train a Mandalorian Child in the ways of Mandalore on a rainy water world planet called Kamino surrounded by millions of aliens who don't care about your traditions or heritage. Kamino didn't have the resources or facilities to properly train Boba in the ways of Mandalore. It was a world set up to grow clones.
Some would argue, that it was the birthplace of Clone Troopers, so certainly it would be a place designed for combat. However I would disagree, and say that the Clones didn't get much real combat training on Kamino. All virtual simulators and brainwashing. A incubator designed to grow living drones that simply followed orders.
Over glorified Droids. Yeah, Boba can't be considered a real Mandalorian being trained there. I would argue that Jango wasn't a Mandolorian either, nor is Pre Vizsla.
However, Pre Vizsla had the right stuff, but didn't have the backing of Mandalore and so he was a Hero without a Home. Sure the people of Mandalore had his back AFTER he shows up with Maul and an army. However before that he was branded an enemy of the state.
Being labeled a criminal and a thug, by the same people you are trying to free, has to play with your head. So I think Pre Vizsla suffered from confidence issues, and lacked the honor of a True Mandalorian. He did a lot of dirt to rise to power, and ultimately sold his Honor at times to get Death Watch back to Mandalore.
If Kenobi kills Pre Vizsla, then I would say that Pre Vizsla is the Mandalorian seen in Kreia's prophecy, as he was more of a Mandalorian then Jango ever was.
First of all.... Seeing that Mandalorians are supposed to be Nomads I'm pretty sure you can train your children where ever you make yourself a home. Also your forgetting that Jango was a Successful Bounty Hunter
, so he can afford the resources to train his own son in the ways of Mandalore if the Kaminaons didn't have the time or interest to help him. Also do you know exactly how Mandalorians raise their children? Do you know the certain Trials.
Pre Vizsla a better Mandalorian than Jango? Don't Insult me sir! So your saying a guy that can't take over a Pacifistic Group of Mandalorians with ease and constantly shows that he simply using the Mandalorian name to get what he wants is better than the guy that became Manda'lor himself, wiped out the Original Death Watch, Killed Tor Vizsla, and most likely won Countless Battles under the True Mandalorian name.
Vizsla doesn't want to free Mandalore, he wants to rule it. Granted he is doing what "The Pissed Off Fans" want by trying to get rid of the New Mandalorians, but he still has his motives for doing so. He is still an upstart using the excuse of bringing back the Warrior ways to rally people to his cause. Plus he's kinda dumb for calling his Group the Death Watch....I mean really I know it's a cool name and all, but you'd think people wouldn't want to join the group that gave Mandalorians a Bad Name? Why not a new name like IDK....the Mandalorian Protectors....