What a strange question “Does it take more time to fly an Orca than it does a skiff?”.
Why do you need this?
Before I learned to fly my Orca, I did the same math just to check the optimal path to train into a good hi-sec solo casual miner. I found that Orca is more effective, universal and faster option to learn at mid-grade level than an Exhumer. But at high-grade level a specialized Orca pilot can be harder to mastery than a specialized Exhumer pilot. It can be problematic to calculate the required total time of learning, because it depends by many factors, sometimes temporar. For example, to learn 4M SP for Orca can take more time than to learn the same 4M SP for an Exhumer, because the Orca requires more different attribute schools: Spaceship (Perception/Willpower), Drones (Memory/Perception), Fleet Support (Charisma/Willpower). The Exhumers requires only two: Spaceship and Resource Processing (Memory/Intilligence). The attribute schools can be remapped once per a long time. So, this is why I’m counting only the reqired SP to effectively fly a specific ship to make things simpler. Moreover, your posted images for Requirements aren’t enough to effectively fly a ship.
Lets say that our basic skills in Navigation, Engineering, Armor and Shields are enought or perfect. How much addition SP we need to built near a perfect solo miner for both Orca and Exhumers respectively?
Then, based on my notepad, to fly the Orca at over 95% efficiency we need a specific set of skills into V, like: Leadership, Minig Director, Shield Command, Shield Command Specialist, Mining Drone Operation, Mining Drone Specialization. I can’t post the entire list, but the total SP for an effective Orca pilot will be around 8M. It’s not a big deal to built a specific list of skills and summ 'em. For solo mining we can dismiss the Mining Director skills to I, but we can’t do it for Shield Commands - it’s our defense versus gankers. The result will be 6.7M SP in this scenario.
To fly an Exhumer at over 95% efficiency we need both Mining Barge V and Exhumers V (which is debatable, but may it be) as the most enormous skills by default. It’s not the main thing here. Without Strip Miner II and Tech II Crystals, both Barges and Exhumers doing a bad job. We need 'em for solo mining. Here is the interesting thing begins! For hi-sec low-grade ores to learn into T2 Strip Miners and Crystals can be cheap and fast - Reprocessing IV (42255 SP) + Veldspar Processing V (256000 SP). So, in this situation an efficient Exhumer will cost between 4.1M and 4.5M SP. Things changes if to train into hi-grade ores like Bistot, Arconor, Mercoxit and Moon ores. In this case, the total amount of learning can be more than it’s required for a perfect Orca pilot. I didn’t done the math.
Therefore, to perfectly train into this
can cost much more than to train into this