Sirius had no qualms going at the death eaters right away - full on. The way things were going, there needed to be a war. And if no one were starting one or the Order not doing enough, Sirius was going to start one. He knew the other Marauders had his back, so it would be a four man war at least. It'd go a bit better if there were more because people needed to realize how wrong it all was and that it was worth fighting for. Sirius knew they weren't the only stand up honorable folks around.
"Dumbledore was always the one people were saying the Dark Dumbass was most afraid of," Sirius pointed out, "and now he's gone. A lot of Slytherins support them and their ideas, probably think they're badasses who want to join him. We have to head them off, but I could see them wanting to gain control of the school." He was doing a lot of talking, but honestly Sirius had thought about it a lot.
"The Carrows are Death Eaters, I think," Sirius replied, "I know family members of mine have wanted to hunt muggles and such, but that was more...sportsmans-like than what those two were saying." And there was the beheading of house elves.
He still grinned at the muggle alcohol. "I've been of age for a while now," Sirius pointed out, "We're adults. And we'll do a lot more good if we can get the Order to include us, coordinate."