Having dedicated haulers and dedicated combat ships is better on both accounts, I think most of the hybrid ships are a trap.
Jack of all trade, master of none. When I'm out exploring, the only thing I want to fight are Domain probe guards, which a Venture has no problem with. A few Gemini to supplement my hauling and surveying gives me a pretty imposing all round fleet that only the largest pirate fleets want to bother with. No civvie Gems either, THOSE are a trap. But rolling around with five Ventures supported by 5 Geminis is a pretty unstoppable exploration force. With Surveying on all of them, there is literally NO planet you can't survey, even the titanic gas giants in nebs.
Mind, this is because I LOVE hurling myself off into deep space, and do something like 100+ planet surveys, plus all the various ruin, station, derelicts you'll find along the way. Coming back to the Core with 4 Synch cores, and 50 AI cores makes the initial investment to get the fleet together well worth it.
Niches exist for a reason, and the Venture's niche is aggressive exploration. Strip mine entire constellations of their wealth with a small fleet of them, then sell off your haul, and buy some proper warships for when you need them. If I'm not fighting, I don't need dedicated warships. If I'm not trading, I don't need dedicated haulers. I need ships that can do a little of everything, cause exploration involves a little of everything.
Which is a classic discussion. Specialists vs generalists.
In the words of the Major, over specialization breeds in weakness.