#3 Paco Godia
Unlike de Portago, Paco Godia didn't claim any podiums during his time in F1, but he didn't require shared drives with some of the true greats of the sport to score his points finishes.
Godia never completed a full Formula 1 season, but the Maserati stand-in scored a pair of fourth-placed finishes towards the end of the 1956 season. While he lagged behind his teammates in the championship that year, we are talking about Sir Stirling Moss and Jean Behra, two very experienced and fast Grand Prix drivers from the '50s.
Even the most experienced drivers struggle when they race intermittently in F1, just ask Jenson Button, so in the circumstances, Godia did a good job. Whether Godia was better than Portago is debatable, but I'll give Godia a slight advantage, partly because the latter was driving a Ferrari, the car that Fangio went on to win the driver's championship that year in.