Taskmaster and walking legs are different. Notice that the top of walking legs comes to a point while task master is flat on top. They're both 3 strokes, but the layout of those strokes is different. Look at them right next to each other, and you should see it pretty easily. They are not the same, and you should not be writing them the same way.

The differences you're seeing between the website and the book for some kanji are due to font. Kanji have been simplified slightly over the years, and some fonts use the more complicated older versions. You'll get used to that pretty quickly as you see more kanji in the wild. It's similar to like a fully serifed out Olde English font versus a sans serif font like Arial or something. Just write the version as you see it in the book since that's going to be the correct handwritten style.

I'm going to justify this dumb mistake by saying that it's been so long since I've had to count strokes, and I was replying to the thread very late last night.