Re:Creators have a really good animation, but it's an action show. YagaKimi needs even less than that. What we need is an atmosphere that fits, and I think Sakurako did that good. Problem with Sakurako was the script not being any special.
Troyca is not a big studio and they contract a lot of freelancer, though, but that's not the point. They clearly are worried about quality given their other projects and I doubt they would approve something bad unless it's an extreme situation.
Fact is that they have only three shows made by them, but all three have some competent animation even though the studio is small. And YagaKimi won't be a hard series to do, since it's pretty slow.