The team have collected 77 points thus far, which is in contrast to the 45 they had scored at this point in the previous campaign.
"I think in general, the first results mean we can be reasonably optimistic about the rest of the season, with a sense that we can fight for wins and the championship," Tombazis told AutoSport.
"However, if I was to score our overall performance, I would only give it a six out of 10 and that's for two main reasons. One is that we are not yet quite where we want to be. In the first four grands prix, we were not really able to fight for pole position and that is one of our main objectives at the moment.
"Secondly, if you look at the actual results, even if it's true we've had a win, which naturally we can be very pleased about, we have also had two very bad results where we scored very few points. However, I reiterate that overall we can be optimistic for the future."
Ferrari were blighted by car problems last season.