There's a lot of suble changes in 6th that make big units better. MSU is not really the way anymore. I think. Obviously don't have enough experience to really know.
I'm thinking they may have made vehicles a bit too fragile.
Well, sure, it's that. But it's also Overwatch (both sides). You get charged, you want more shots to thin them down. You charge, you want more assaulters to make sure you got there.
It's psychic powers, blessings. The bigger the unit, the better that blessing is. Novas, the more targets there are, the more damage they take.
I think we are undervaluing vehicles esp when there is a mass of 19 of them
Sure, but let's take a typical draigowing. For me, we have a like 1000 pts or so in the deathstar (1100 now, cuz I'll buy Coteaz for free rerolls, on
everything), then there';s usually some psyflemen, other stuff. These days, gonna have a Stormraven, too.
Pallidins kill a razorback a turn, so do the psyflemen, probably. But you have 19! You probably kill like 2 pallies. But then turn 3 comes along. Multi-charge! Which has been nerfed. But that's great, no one cares. I'll get 6 rhinos in that charge, no problem. Krak grenades, so everyone's Str 6, if I didn't manage to get it up there with hammerhand already (probably) + however many hammers I bring. Almost everything hits cuz I only needed 3's and I get rerolls. They're all dead now, I may take more damage in the explosions than you managed to do to me all game. Turn 4, same thing.
Or completely different list, I brought a Land Raider (I'm kinda known for that). The only thing you have to deal with that are the psyflemen, who aren't going to do a great job of it.
Obviously I'm painting a rosy picture, and no plan survives contact with the enemy. I'm also not trying to critigue your list building skills. But I'm not that worried about the bazoillion+ razorback lists. This same basic battle plan is applicable to Genestealers, fiends, BA, horde orks (which are disgusting now). Really any large or very tough units that can get to you quickly.
Rhinos/razorbacks die dependably to shooting now, and
quickly to assault.