Yes, should be fine as long as the other fish are large enough not to become dinner.
What else are you thinking of keeping? Any reason you're doing all Dels? I love how they look but some of the other upper jaws are fun, like the Pollis and Sens because they tend to be a little more active and interactive in my experience. But I do understand that the Dels kind of look the most 'ancient' for upper jaws.
I’m very limited on space and can probably do only 2-3 setups, only one being of any size (75g). Consequently, the largest would house the dels and maybe a couple severums, or an oscar.
