I have a Kindraa creation year for you and I think it provides the probable answer you seek to the Smythe-Jewel origin question.
TLDR: It looks like Smythe-Jewel and also Matilla-Carrol were always 1 Kindraa (each) with a hyphenated name. But with the caveat that while Matilla-Carrol were definitely there, FM: CC does note that two of the smaller and less viable Kindraa had been swallowed up in internal Trials in the first year, and we don't know which ones those two were. However the odds that Smythe-Jewel were that seem remote to me.
Turning Points: Foster page 10. Under the Second Jewel Cluster. It says: The Second is Kindraa Smythe-Jewel’s oldest Cluster. The Second Strike was created alongside the Kindraa itself in 2835.....
For context Nicholas Kerensky was killed and the Widowmakers absorbed in 2834.
We know in the earliest days of the Clan it was more like different individual warriors/trinaries/clusters fighting amongst themselves. What started as Kindred Associations a "term that evolved over a few years" (FM: CC page 38) to Kindrasc then Kindraa.
FM: CC's Mandrill history section also says in the earliest incarnation of this, a Kindrasc was basically just another name for a Bloodname House, or a collection of minor Bloodname Houses that had pooled their resources together. Because Kindrasc could span members across multiple units or even multiple Clans it was a helpful way for a warrior to identify their allegiances. But in those days the Clusters, the enclaves, all of it were still just Clan Fire Mandrill. So it was just a non-standard variation on the concept of Bloodname House politics back then, like those found in other Clans.
It then specifically says the next step in that evolution happened after Kerensky's death and the Widowmaker absorption. It says those events had a profound effect on the Mandrills. With Kindrasc Sainze bringing together two clusters it controlled and challenging the Wolves for a Dagda enclave. They won, but rather than turn the enclave over to the entire Clan, they declared it belonged to Kindraa Sainze. They then expelled non-Kindrasc/Kindraa Sainze members and something resembling the Kindraa we know was born. Not too long after that, the Paynes worked to match that move by forming Kindraa Payne. Then Faraday did the same.
FM: CC says in the weeks after that, "countless alliances were made, and fought over, and broken and reforged." By the time that cycle was complete, the Clan separated into Kindraa had appeared. A few paragraphs later it says the Clan had reformed itself into 14 Kindraa.
(side note: Kindraa Matilla-Carrol gets mentioned specifically here, assisting Kindraa Faraday in repulsing the Burrocks, who were first to notice the new factional realignment of the Mandrills and thought that would make then an easy target, so it was another hyphenated Kindraa in the early days as well)
So in terms of timing, Kindraa Smythe-Jewel's stated founding year nicely aligns with the period of time where the actual Kindraa were being formed as distinct entities, rather than just a version of Bloodname House politics and Bloodname House alliances by another name.
Therefore it seems likely to me that Smythe-Jewel was always 1 Kindraa. if Smythe and Jewel stood as separate Kindraa, they only did so for a matter of months to maybe 1 year.
HOWEVER.. big disclaimer. It says that the Clan had reformed into 14 Kindraa, but it took the rest of the Clans about a year to confirm the exact number of Kindraa. By that time, "two of the smaller and less-viable Kindraa had already been swallowed up in internal Trials of Absorption."
So there is a chance they were separate, at least two Kindraa were gone. So in the first 12 months of this Kindraa reshuffle, AFTER 14 Kindraa were established, 2 were absorbed almost immediately. It sounds like they were small and weak and didn't possess the assets needed to stand independently and remain viable by themselves for long.
By probability of odds, I doubt it was Smythe-Jewel. I'd give that certainly less than a 50 percent possibility. It seems much more likely that happened to a couple small more obscure Kindraa that we've never heard of.
If I was a gambling man, I'd bet that Smythe-Jewel was one of the original 14.
