Early game bidding as Greyjoy
The answer to this question will be very heavily dependent on your group, and their groupthink.  In my experience, often bidding 3 on the blade would not result in getting it (I would probably be 2nd or 3rd, with someoen else going all in on the sword), while a bid of 2 on the Raven would probably be enough to get me at least one star (with someone else bidding zero after going all in on the sword).

Given that there is a large advantage of having the Sword token, versus simply being 2nd on that track, I think your strategy of bidding enough to get the Sword makes sense.

From a game theory perspective, since all bids are spent, you want to bid just ahead of a large clump of opponent bids, such that you gain a significant advantage over them while only paying slightly more.  If this is not possible, it might be best to bid 0 in that case.

If your group very consistently lets you win the sword for 3 (but not less), and consistently does not let you get stars with a bid of 2 on the Raven, then I would recommend bidding 3 on the Sword and 0 on the Raven, conserving your power, and then bidding higher on the Raven in the second bidding round.
Also, if your group tends to always bid the same amounts like this, they are very exploitable game-theory wise.  Bid either just above their usual bids, or way under them.