Well, yeah. I was sort of assuming that you won't use a TCXO or even just a cheapo quartz crystal, because it doesn't make a lot of sense: You've now thrown money at something that will relatively quickly desync anyway.
I mean, sure, the TCXO will mean that you only start seeing a phase difference between the two after weeks instead of minutes, but what's the point of that? I you want them to be at the same phase, you'll need to sync them at some point, and you do that by using a common clock source.
So either you shell out some effort for a real solution (power line is nice, and also qualifies as a common clock source as I've predicated), or you don't. And if you don't, there's no point in using a precise-ish clock at all, and you'll likely end up with very quick desyncing.
I mean, sure, the TCXO will mean that you only start seeing a phase difference between the two after weeks instead of minutes, but what's the point of that? I you want them to be at the same phase, you'll need to sync them at some point, and you do that by using a common clock source.
So either you shell out some effort for a real solution (power line is nice, and also qualifies as a common clock source as I've predicated), or you don't. And if you don't, there's no point in using a precise-ish clock at all, and you'll likely end up with very quick desyncing.