I have both blogs and podcasts on my site. It works really well.
The biggest consideration in my opinion is whether you’re making a forever decision with Substack because it’s really a closed system compared to Ghost, where you can export your content and switch to another platform if you want.
Ghosts’s API makes it really easy to integrate with things that’s aren’t native integrations. For example, I hired a developer to create a two-way sync with MailerLite because my business case requires email automations not offered by Ghost. Unless Substack has changed I don’t think that’s possible.