True, but in the original Elite you couldn't buy a T9.
Reduction in profitability from having most of my hold taken up with shields and cells seems unlikely. In reality, you would go for a fighter escort. You would expect to be more likely to get attacked with a hold full of expensive goods, at which point hiring mercenaries should be cheaper and safer than fitting massive shields.
As things stand, I would have to convince my son to play the game and bribe him with extra mobile data allowance if he acts as a fighter wing for my trade missions
At that point it ceases to be a game, things are getting too complex.