HCs take a similar slot as BCs in Chaos. They are kinda the same class of ship, but for some reason they decided to call them heavy cruisers for chaos, and battlecruisers for IN.
I guess it's fine calling it a HC, although it would have the same restrictions as BCs (I.E you can only buy one
BC/HC/CG for every 2 cruisers)
Any thoughts on the stats though? Decent? I'm trying to write up an eastern fringe list, and the Ignus has the same storyline/feel as the Acheron, where it was experimental, and no one really knows if there is more than one.