That's the "hiccup" in all this.
One Stern Ritter Y was apparently Stronger than the other since Zaraki easily wiped the floor with Loyd, but Royd seemingly beat him pretty easy.
But there was also the same problem in the Espada since some of the higher ranked Espada seemed weaker than some of the lower ranked Espada.
I myself still find problems with Yammy being Cero Espada tbh.
It's worth noting that it was kind of implied that the Stern Ritters weren't fighting seriously. In chapter 502, after Haschwalth felt Byakuya's reiatsu faded, he remarked that it is dragging on or the battles are taking longer than expected(Viz). Fake Yhwach's response was that the Stern Ritters only flaw is that they are too permissive. MS translated it as naivete was their flaw, so that works to, I guess.
By coincidence, after he said that, here comes Kenpachi, out of nowhere, carrying 3 dead SRs above his shoulders, which only reaffirm what Yhwach(Royd) and Haschwalth were previously saying.
We learned in chapter 503 that Stern Ritter Q wasn't even fighting, and basically spent the time explaining her or his abilities to Kenpachi. Stern Ritter R was roaring most of time. The only one that put up a fight out of the bunch by Kenpachi's own admission was Stern Ritter Y Loyd. Unfortunately, Loyd was imitating Kenpachi, who we know was severely suppressing his power.at the time. So even though he put up a fight, given that he was imitating someone who subconsciously was suppressing his own power, it implies that Loyd's own power was being suppressed as well
Kenpachi being the big shot after killing 3 SRs thought he could take on the boss, who was later revealed actually to be none other than Stern Ritter Y Royd, Loyd's younger brother. Oh, the irony.
Royd was imitating Yhwach at the time he put Kenpachi to sleep. However, his imitation abilities only extends to copying appearance, memory, and mentality. So, that pretty much tells us he wasn't borrowing the real Yhwach's power, at least in terms of power level.
He pretty much said it when he apologized that his power isn't enough in ch. 509
In conclusion, there is a high possibility that Loyd was as strong as Royd, the one who defeated Kenpachi. Unfortunately he imitated the wrong person, rather than using his true power.
Edited by Kensei13, 06 July 2013 - 02:19 AM.