Both forwards have 11 goals, with Sundowns having five games left in the season to City's four.
Baroka attacker Gift Motupa is third on the league's top scoring chart with nine goals, while SuperSport United hitman Evans Rusike is three strikes off the pace.
Mosimane, however, says he is more concerned about Tau being named the Absa Premiership Footballer of the Season, a target he set earlier in the campaign.
"Yeah, I don't know. 'RamaG' scores. RamaG's got more experience you know. RamaG plays to score," said Mosimane when asked about the pace-setting duo's prospects of winning the prize that was clinched by Lebogang Manyama last term with 13 goals.
"Percy must also pass, assists. Percy must move out of the box. RamaG doesn't move out of the box, he's waiting there to hammer it and he hits it well.
"And they play for him, because he's the one who scores. We don't play for Percy. We have Khama [Billiat], we have [Gaston] Sirino, we have 'Vila' [Sibusiso Vilakazi]. Anybody can score in the team, so it's a bit difficult.
"For me I like the stress. It gives him maturity, it gives him experience and he must go for it irrespective of me.
"I'm not worried about the Golden Boot for Percy. What I'm worried about is player of the year. Golden Boot, then he doesn't pass when he's meant to pass."