The only thing ChocoRose (my OC x Canon pairing between Dark Choco and Vanilla Rose) and MercurialCoral (credits to @oneeyedbeep26 for creating this ship) is that the women in these ships are tall queens, with Vanilla Rose quite literally being a giant in the cookie world. She's not human size, but other cookies still have to risk getting their necks broken just to make eye contact with her.
So...here is how I imagine an interaction between the two would play out.
I don't know much about Mercurial Knight and Crimson Coral Cookie's personalities, so I apologize if either of them are OOC.
(Crimson has a two-legged form she can shift into here coz...wynaut?)
Vanilla Rose and Dark Choco walked in the forest together, their hands entwined.
"I've missed this." She uttered. "Being with you and going on walks together."
He smiled back at her. "I've missed this as well. I'm glad to be back."
She giggled, pulling him in for a small kiss before eventually continuing their walk.
Along the way, they encountered a gray cookie that smelled strongly of metal and a crimson cookie that smelled of the sea.
Vanilla Rose looked down...and down...and down...then grinned, recognizing the gray one.
"Mercurial Knight Cookie!"
The gray cookie bowed. "Vanilla Rose Cookie."
"You don't have to do that, don't worry." Vanilla Rose assured.
The gray cookie then noticed Dark Choco, and the two gave a respectful nod to the other.
The crimson cookie's gaze hardened as she readied her spear.
Dark Choco extended his hand out in front of his fiancée.
"It is alright, my Sea." Mercurial assured, putting a hand on the crimson woman's shoulder. "Vanilla Rose Cookie is the daughter of White Lily Cookie. She and..."
"My fiancé." Vanilla Rose confirmed, wrapping an arm around Dark Choco with a proud grin on her face.
Mercurial nodded. "She and her fiancé mean no harm. Do not worry."
The woman put down her spear, though she wasn't completely relaxed.
"Vanilla Rose Cookie, this is Crimson Coral Cookie."
"I didn't know Mercurial Knight Cookie had a lover."
She extended her hand out for Crimson Coral Cookie to shake.
Crimson Coral Cookie looked up...and up...and up...and up...and...by the witches! UP at Vanilla Rose Cookie.
She remained silent for what felt like an eternity, likely assessing if she should be trusted or not.
Vanilla Rose began to fidget, feeling restless and anxious at the other's lack of response.
Just as she was about to put her hand down, Crimson Coral took the larger woman's hand and the two briefly shook hands.
"It is...nice to meet you as well."
"So...what do you say we all walk together? Just for a bit."
"I would not be opposed to that." Dark Choco said, a small smile on his face.
"I would not be opposed to that either."
Mercurial Knight then turned to his lover.
Vanilla Rose laughed. "Off we go then!"
She scooped her lover up in her arms, giggling at the way his face turned red, and started running.
The other couple followed after her.
"This...Vanilla Rose Cookie is...very peculiar in comparison to the other two-legged cookies I've encountered." Crimson Coral uttered.
Mercurial Knight nodded in agreement.