Happy new bass day!
I don't know Guild history so well, but I've seen Starfire basses with either a single bridge or neck pickup. Were these offered at the same time? The Chris Hillman model, for example, has a bridge pickup only.
The most interesting Guild bass I've personally played was a M-85 with a Bi Sonic in the neck position and an HB in the bridge. The body was deep, like an ES 175. I was all fired up for getting to play a bass with an original Bi Sonic, but I gravitated more towards the bridge pickup. There was a switch on the bass that either cut all the top end or all the low end from the Bi Sonic, so I don't think I really got to hear what it was capable of. The output seemed weak in either setting, so maybe the pickup had degaussed or something? The bridge humbucker was pretty meaty by contrast.