Playing as a Mounted Archer solves all your problems. Playing as a Foot Fighter you will never beat a Tamer. Adding increased White Bear Spawn time does nothing. People will just wait it out, get another one stable it, and keep doing it until they have a full stable.
White Bears are not Breedable, Brown Bears are. So on Release any Tamer Worth their salt is going for Brown Not White Bears, so that solves that problem. Funny enough our Brown Bears will be stronger then the Current White once we breed them. And Minotaur is more of a Valued pet as it has Charge and Knock Down, Dominated Pets like the Minotaur are naturally stronger then tamed ones as well, being on Pare with Insect Death Knights for Combat. Shore Prowler is better too as it's basically a White Bear for damage but with better defenses. Once again Solution, don't intend to fight a tamer as a foot fighter. Foot Fighter is by design, meant to be balanced around other foot fighters. Foot Fighters have a lot going for them, a lot of weapon and armor choices, that scale based on type of weapon/armor chosen for the foot fighter. And clades that buff them up. As well as only needing to spend 100 primary points to obtain ranged combat. But 1 class can't beat all other classes. The Game was never meant to be 1 class as the only played class.
Even in Mo1 days Tamers/dominators were often the bane of everyone's hate. But Mounted Archers always beat them. So they had their own balance Demon Bats/Spider Queen and Lizards as ranged attackers to try to fight Mounted Archers. But even then the Tamer loses to Mounted Archer. Because those pets have less Hp then the Tank pets the bears, and die twice as easy to ranged attacks. Then we have multi pets Crocodiles/Bats/Terror Birds/Cougars where we could have 3 of each with maxed lores and herding skills.
If I do the math you could nerf a Max Level White Bears Hp and literally divide it's hp by 3, and still have more then 300hp on that lv125 White Bear. Obviously the devs will never take away 600Hp from a White Bear, but even if they did this should show you that Tamers are not meant to be balanced around Foot Fighters.
Here's the secret sauce: A Terror Bird in Mo1 was the only Pet capable of catching a player on a Mount. Tamers pets are balanced around Move speed because Mounted Archers are what counters them. And Because The Developers don't want Tamers to be World Of WarCraft Hunters where in Warcraft Pets are useless and Weak. In Mortal Pets are a Second Play Style, a literal Second Class called a Beast Master. As Long as they don't make a pet faster then a Horse you have nothing to fear, because there will always be Mounted Archers to counter them. But Tamers Counter Foot Fighters. Dex Fighters/Foot Archers Counter Mages, Mounted Mages Beat Foot Fighters, Mounted Archers Beat Foot Archers and any mages, Mounted Warriors Beat Foot Fighters, Tamers, and Foot Mages. And Hybrids are basically a Build that can beat a Foot Fighter Or Lose to a Foot Fighter depending on skill.
In essence Foot Fighters are the weakest Class to start out with. Where you guys start to really shine is when you have end game armor and weapons. But Anything less then Ogh,Cronite,Tungsteel and you guys get clapped by other classes. Foot Fighters can't defeat any class with a mount or pet.