I've used the Arcana Cleric Frontliner one (complete with Azorius background), as well as the Soulknife, in high-level oneshots, and they performed quite well. While the EK didn't go through much and I can't vouch for it in tougher scenarios, it just didn't care in simpler encounters and did work as expected there, which was basically steamrolling things.
The cleric however went through multiple deadly encounters (I think it was 4), as part of a 3-person group no less, and with two less than stellar players, and was excellent. Not gonna claim I didn't break a sweat, but damage, durability and support were all high and the resources were enough to last throughout the encounters; I could still do a couple more with what I had left by the end of it. And I'm pretty sure I didn't play the build at its utmost potential.
I am also running the Ride of the Valkyries paladin in a campaign where I knew magic item access would be easy (and indeed, I got my Str item quite fast) and that having a mount wouldn't be more trouble than it's worth (also turned out to be true), but we've only reached lv7 so far there, so I can't comment much here. It's been stellar for the levels we've gone through, although I'm playing a more support-y version due to the group's composition and experience (picked up Inspiring Leader already at lv4 and am using the Blessed Warrior fighting style for guidance); ultimately, however, it's a relatively straightforward build, especially early on, so all I'm really saying here is that Vengeance paladin is nice in tier 1 and tier 2. Haven't had the chance to try the higher level strategies yet, obviously, but I doubt there'll be much issue.