I am following Hasan from past few years when he developed an FB token generator.
Now i am following his every video and I am trying to implement a few email applications along with some smtp.(amazon ses, own domain smtp, mailchimp and posta)
Mailwizz and Mautic both are frontend applications and you can send emails by connecting any smtp (like phpmail, sendgrid, amazon ses etc).
You can use mailwizz as saas application, you can offer services to your users or any end customers. In mailwizz you have more smtp options (amazon ses some regions are not available in mautic)
Mautic mail sequence is good as per my observation.
Mautic having drag and drop template builder, same available ( addon) in mailwizz too.
And As per my knowledge, you have to install Mautic in a single droplet. and for mailwizz you have to install webmin new droplet and then you can install mailwizz, in webmain droplet you can host other websites too.
I don’t have idea of both in the single droplet, but as per my knowledge yes you can host both in single droplet ( mailwizz (webmin) is main and mautic in another folder of same droplet, i didn’t try but its possible), but droplet resources should be high.
As per my experience mailwizz is good in terms of long-run and having more options than mautic.
Note: These are my observations and experience, Hasan will guide you if any wrong in my words.