I think you are wrong this time.
Ok Arantxa won a slam in 1998, but she had QF at the Australian Open, same as Venus, Qf at Wimbledon same as Venus, and QF losing effort to Venus at the Usopen, so clearly Arantxa had a greater grand slam year than Venus.
I even bet that Arantxa had a greater grand slma year than Novotna.
Won: Sydney (Tier II), French Open (GS)
Final: Eastbourne (Tier II), Montreal (Tier I), Tokyo (Tier II)
Semi-final: Lipton (Tier I), Rome (Tier I), Los Angeles (Tier II), Filderstadt (Tier II)
Quarter-final: Australian Open (GS), Wimbledon (GS), US Open (GS)
Losses: 3x Martina Hingis (*), 3x Monica Seles (*), 2x Anna Kournikova, 2x Venus Williams, 1x Anke Huber, 1x Andrea Glass, 1x Patty Schnyder, 1x Jana Novotna, 1x Julie Halard Decugis, 1x Lindsay Davenport, 1x Anna-Gaelle Sidot, 1x Amanda Coetzer, 1x Irina Spirlea
(*) Includes one Fed Cup rubber
lost to Huber, Hingis, Venus Williams, Spirlea, and Kournikova at the Australian Open, Wimbledon, US Open, WTA Championships, and Miami respectively.
Not as bad a year for ASV as I expected. I was probably thinking of one of the later years when I remembered her playing piddly little Tier III clay court events in places like Egypt. Her record seems to be littered with more bad losses than Williams, but she also played a lot more than Williams on both clay and indoors. Curiously enough ASV seemed to be most consistent on hard courts in 1998, getting to a lot of semi-finals and finals, and losing to top opposition.
Having looked at both of their records, I could just as easily pick ASV as the #4, but I think I'll stay with Venus. ;-)