While the pack Tigers are a straight upgrade to the tech tree Tiger H1, it’s not a huge difference. The track armor doesn’t render them immune to anything a properly angled H1 isn’t already immune to, namely the American 75 and 76mm guns. 85s, 90s and 17 pounders still rip right through, let alone the real high pen stuff they see in uptiers.
All it does is make them resistant to the 75mm flat on, and make angling against the 76mm more forgiving. And those guns are still free to aim for the cupola for an easy disable.
Were there a BR step between the H1 and the E, they’d belong there. But as none exists, they’re fine at 5.7.