In summary:
1) Structure is cheap, but countered by lots of different weapons (including the super-long-range sniper weapons)
2) Armor is expensive, but is only countered by short-range weapons. On the other hand, even lowly fighters carry anti-armor weapons.
3) Jammers are middlingly expensive, and only mid-range and long-range weapons counter it (once plasma bolts are switched to anti-deflectors).
4) Deflectors are expensive and only occur on large units (same as shields before them), and the only long-range anti-deflector weapons are also on large units (and small units with short-range ones are rare)
So for a lark a couple of weekends back, I put together a rebalance in order to teach myself how the XML files fit together. Interestingly I had a similar fourth category.
I made all squad ships defense evasion, all starships defense armor, all turrets defense structure and all huge ships defense "capital". Then balanced the capitals and anti-capitals to have extreme range, all squad ships to be fast but short range and the starships/turrets somewhere in the middle. It was a fun variant and had me staging squad raids to take down a system's anti-capital fire before popping in with the "big guns" on a souped up Ark/Flagship to pulverize the rest of their defenses.