Alright let's bring some math and sanity to this entirely far too long opinion war.
First, I will agree that you aren't killing anyone with 4k HP in two hits. But remember fury is fast as fuck and you can land 5 hits (which can animate entirely in 8 tenths of a second) in the time your brain perceives two.
However, the rest is actually fairly easy to work through.
Koston was kind enough to provide some stats so...
Build #1 with rare pelt - 5083.5 average damage screen, 44513 AR, 9310 life
Build #2 with Cerebus - 4981 avg damage screen, 43276 AR, 9090 life
Now I built a calculator to do all of this for me, and I will show some results and also discuss the assumptions of the calc and the results it's spitting out.
First off, it's an averaging calculator. Average number of hits to kill X amount of HP. Takes all of the damage modifiers (ds,cb,ow) into account. Also takes into account 75% block and defense so we can gauge approximately how long a duel will last in seconds, and converts that into number of seconds to kill. That's how we can can get an average win percentage against our opponent. More than happy to share my excel formulas if needed.
So with the rare pelt vs a paladin that someone plugged into my calc, it looks like this:

And with the Cerebus instead it looks like this:

The Rare pelt is clearly better on average. It offers more life, ar, damage.
But the Cerebus isn't that far behind.
And a note on open winds triggering. Cerebus setup has a 43% chance to trigger OW. So my calc averages that amount of damage into the total.
If Cerebus triggers the open wounds on the first hit, it looks like this:

So can Cerebus be better sometimes? Yes, it can.
But only sometimes. Only if you get lucky.
At the top level of melee dueling, you're going to be dueling some of the other same people at the top a ton. A couple extra percent of average wins can be the difference between top 3 and merely top 10.
Can the Cerebus user break the top 3? Yes. Will they stay there as consistently as the rare pelt user? No.
So there's your answer. You are both somewhat right and somewhat wrong, but Koston is more right than Ukon on the merits.