Tasha: "Gee, I don't know Captain. Maybe we could tow the fucking plague ship away from that uninfected planet over there. You think?"
I'm not sure I understand the objection here.
Firing at the ship was obviously unnecessary, as the tractor beam could handle the stopping easily enough. This fact would not have been unknown to Yar. Tractoring was always an option, but preceding it with warning messages was prudent. Preceding it with warning shots would have been rather unnecessary, I'd think, as it had been confirmed the Tarellians knew they were not welcome and were being met with a superior force, and still weren't turning back.
What Yar was doing was saying "Captain, we can
do what Electorine Valeda is asking", that is, using weapons fire as the method of stopping the plague ship, and Picard was asking Yar to consider that this would have unnecessary consequences. Disabling with phasers was the Havenite solution, neither here nor there; destroying with phasers would have been the Alcyone solution. Picard told Yar to stick to the Starfleet solution.
"first we'll allow them within transporter range, and only after that happens, we'll block their transporter with our tractor beam."
It doesn't seem as if the tractor beam would prevent transporting. After all, Wyatt Miller beams over easily enough!
Rather, it seems our heroes just yanked the Tarellian ship back from within
transporter range to outside