They actually do! Here's a link to Matas VoD where they do: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-G9Be4SppzbI.html Heavenly joins the VC at about that timestamp, around 46:30
You guys did great on this! Had a similar idea, where if Helldiver was an anime Mata and Zen would have been top secret projects Super Earth made to counter the bugs and bots respectfully. eventually recruiting Mouse and Haruka to their team, with Haruka eventually finding out she was part of a failed project to counter the illuminate if and when they arrived.