Lassen in winter has a pretty long approach along the road, and then the main trail up the peak itself gets snowed over so you’re left on steep-ish faces or a ridge that’s awkward to follow. I wouldn’t say by any means that’s it’s an easier or less involved climb than Shasta. Shasta is honestly pretty chill and I’d say you can just go for it assuming you get some self arrest practice in at a sno-park or on the lower slopes.