To emulate the behavioral patterns of the Arachnids, the Holoprograms needed to be run by the Red Queen personally on the matter. Anything less was totally unacceptable because even though the Obscurus was a very advanced ship, the basic computers would achieve only a realistic rating of around 70%, and Arcturus was obviously going for 100%.
He was rather a perfectionist, so going for anything less than perfect wasn't an option for him, and with the Red Queen's processing power, it was as easy as breathing to create ultra-realistically behaving Arachnids.
Arachnids were smart; there was a common misconception that they were either stupid or that they were all controlled by the Hivemind or the proxies, meaning the Swarm Queens, Superbrain Bugs, and Brain Bugs.
