The time period is the General War so a lot of racks aren't really present.
Since seeking weapons are a set of rolls with certain things able to defend vs them effectively the dfferent ranks get abstracted a little.
A racks should be gone by Y175 -and the B rack is really an ammo upgrade, as essentially is the D rank. Ammo restrictions are below the level of the game detail in this game, so from what I can see of the game relased in the blogs really everything is unlimited ammo, removing the difference between A and B racks. Though when the game comes out we might find an ammo setup in place. The E rack is covered by the anti-drone rating - as really is the G rack. That or the G can fire normally or add to antidrone rating as a special rule. The F rack is also pretty much gone by the time period but can be simply simulated by adding the Slow Loading trait to an F rack.
The C rack is the rapid fire, and can put 2 drones a turn - simply done by doubling the Attack Dice those racks give. Same holds for the Type H on Starbases.
So in short, yes the system can certainly conceptually deal with the range of drone rack variations but the differences may be somewhat invisible, or abstracted out into Traits in certain cases.