The Amiga 1000 chips were fabricated in 5 micron depletion-mode NMOS (mostly passive pull-up transistors), not CMOS (complementary P and N channel transistors). So a typical low-speed 2 input passive NAND or NOR gate would have 3 transistors, not 4. However, a lot of the logic was done using chains of pre-charge evaluate dynamic logic, with different transistors gated during different clock phases. So, there is no straightforward conversion.
The count of 22k transistors for the Agnus also seems wrong, as the die size, transistor size, and fabrication technology of the Agnus was not very far from that of the MC68000, which was reported to have over 60k transistors.
Also, the original first Agnus chip was fabricated by Synertek (possible later revisions may have been done by MOS Technologies, after the Commodore purchase of Amiga technology).