Achilles heel of having to source your ranks from other populations, who won't want to be consumed, & will do everything to adapt ways to prevent or undo it. It's clear that certain things about a Borg drone ARE deadly if removed, even from liberated ones. So maybe there are some methods at play to keep from giving up a drone to liberation, but as will any creature fighting for survival, we came up with workarounds, & solutions to counteract it?
I had a think about all of that stuff before posting actually and I did tend to lean towards the opinion that they do share the same knowledge, more or less.
With Seven's roll as a support drone, rather than a designated systems drone, she no doubt would have knowledge of all systems irrespective of differing opinions on this subject. So I have to rule her out as a deciding factor here.
Yet what can't be ruled out is that she was part of a unit within her cube that played a support role. So there are no doubt many others like her in each cube. Most likely even many support units within the one cube. So that would still be a huge risk of information leakage when talking about just that type of Borg alone.
The main reason I'd tend to believe that all drones posses the same knowledge is that it makes for quicker adaptation in the event of unforseen circumstances. It means more minds working on more problems.
I don't view the Borg as simply worker drones that do their job only in the physical realm. Such as repairing something using their hand tools. Rather they also apply mental cohesion to tasks to adapt and repair or build most effective and efficiently.
Seven once said that for one single problem, there is the entire collective working to solve it. Therefore any encounter with them gives them the ability to think things through with as many minds that are available to do so.
The Borg aren't limited to subspace communication time delay because they use transwarp techniques it seems and their communication is instant. So the only thing they have to worry about when it comes to allocating minds to the task of solving a problem is pretty much just the priority of the problem and how many free minds are available to solve and the processing speed of each drone. So if there are two problems of the same priority level that come about at the exact same time and need solving instantly, such as two photon torpedoes launching at two separate cubes. Then the collective is forced to split the labour in half and devote half the available minds to the task of preparing for the impact of the torpedoes and how they will react to them.
This ^ kind of situation would be severely inhibited if the collective made the choice to not bring all of their drones up to the same level of knowledge. Rather than a split of 50/50 of the overall available minds of the entire collective. They would be limited to only those that were about to be affected by the incident. Therefore solutions would come slower, and there would be drones left around doing things of lesser priority simply because they just could not add anything of value to the solving of the current problem.
My theory on Picard not having the knowledge that Seven does is that he has no cordical node anymore, and Seven does. Her implants were clearly more difficult to remove than his. Perhaps because of time. She still had the eye thing and her hand as well. It certainly was two completely different types of freedom from the collective that they both experienced. She could barely escape it, and it seeped into her personality to the point it changed her mannerisms and way of speaking completely from what she was as a child and her body held onto parts of the technology as though it was apart of her. Whereas for Picard it was just like a bad dream basically and it seems that practically no information from the cordical node was retained within the biological part of his brain.
