I mean, as far as crack Touhou pairings go, this isn't that far-fetched - they have at least interacted in canon, which is more than one can say for some other crack Touhou pairings.
Nonetheless, I kinda like Tama's portrayal of the pairing. Their other pictures of Sanae x Doremy have Sanae being doggedly persistent in her affections for Doremy. On the other hand, Doremy is a bit weirded out but will sometimes show her dere side towards Sanae, which is nice.