I am slightly confused, and perhaps misunderstanding your framing.
I do use DMARC and SPF in the fashion you described. In my environments I typically need to take every measure to ensure only authorized services/servers/senders are sending, via authorized hosts and IPs, and this often changes based on subdomain, so that’s why I use strict alignment. Personally I strive to keep various services strictly separated by (sub)domain.
I thought it might just be ambiguous language. It wasn't clear to me what you were trying to say and it could be read as implying what I have seen (incorrectly) stated in some DMARC descriptions elsewhere. Just trying to prevent any misunderstandings from anyone reading the thread and improve my own understading by checking that I got it right before posting. Thanks for clarifying what you ment :).
I do use DMARC and SPF in the fashion you described. In my environments I typically need to take every measure to ensure only authorized services/servers/senders are sending, via authorized hosts and IPs, and this often changes based on subdomain, so that’s why I use strict alignment. Personally I strive to keep various services strictly separated by (sub)domain.