If we're going to play "Jensen says" I have some relevant Jensen quotes. While Jensen definitely sees Sam & Dean as the foundation and center of the show, that's not all Jensen says. What does Jensen think about Cas, Misha, & the role of an ensemble cast? Let's take a look.

To start out for context, Jensen, and J2, from the beginning have asked for an expanded cast. This was mostly due to workload, but as you'll see in further quotes, this is also Jensen's creative and emotional opinion on what keeps spn ticking as well.

(TVG Oct 2007)

Jensen early on praising Misha and what he added to the show in his role as Cas and saying he's "really happy Misha's part of the gang" before S5, which was when the show's creator made Misha a regular.

(SPN Magazine Aug/Sept 2009)

When Cas was removed in S7, Jensen called this "a big loss" for the "storyline and the show and the characters" not just due to workload and that "Misha is family"

When Cas/Misha returned to SPN in late S7, both Jared and Jensen were excited. Jensen reiterated "he's one of the family."

Jensen has referred to Cas as "one of the most loved characters on the series"

Jensen at Jibcon, May 2017, discussed what "drives the show" and said it was the relationships between characters. He included the bro bond and Dean and Cas "and even Crowley" in that.

Jensen, in 2014, talking about Misha and Mark S being series regulars and their characters being "integral to the stories and to the boys" and that their promotion on the show to regulars "was welcome to us."

Jensen, in 2016, talking about why spn being only him and Jared wasn't sustainable long term, and how having Misha on the show playing Cas "worked so well" and how Misha has contributed to the creative, welcoming space they hoped to build on set

Jensen, in 2016, speaking in general about how "the comraderie" that exists among ALL the cast and the crew is one of the reasons why spn works.

To illustrate how Jensen views the expanded family characters/ensemble of SPN, he was a vocal supporter for Wayward Sisters. He even said he felt conflicted about them doing their own series just because he wanted these "valuable" "great" "amazing" characters to stay on SPN.

Sam, Dean, and Cas (and others) are all reasons the show has endured. Jensen affirms the bro bond as the center and also deeply respects and appreciates what Cas and other characters add to the show. Here's Jensen last year eloquently praising the role of the ensemble characters