I figured most people recorded from the ground up, doing drums and bass, rhythm then lead.
That rather assumes that everyone is using the same instruments in all their songs {I'm assuming two guitars, bass guitar and drums because few people refer to other instruments as 'rhythm' and 'lead'}. Unless by "drums" you count percussion, "bass" you count double bass or synth bass, "rhythm" you count any instrument that forms the or assists in the rhythmic foundation and by "lead" you count anything that, well, leads, breaks, counterpoints or solos.
Now, if you do, then that takes how the song comes together into a whole different realm.
There's obviously more to it than that, but I'm just trying to rationalize why people do it backwards.
I think alot of it is to do with availability. I reckon if every one of us had access to a drummer who could come in at virtually any time to lay down their bit, you'd see many have a very different schedule of recording to the one they've described.
The answer after reading what I have written is, whatever works for you and what ever works for the style of the music.
That's the thing. For me, it really depends on the song, what's going to be in the song, how simple or complicated it is......
For me, it depends on what the scenario is.
As a general rule, songs will begin with bass and drums, bass and percussion, guitar and drums or guitar and percussion. If the guitar is going to be acoustic, if I'm recording it with the drummer then I'll DI an electric and count that as a scratch. I spent too many years fighting the drum bleed in my acoustic guitar tracks !
The only time I'll do a scratch track is.......I really have zilch need of them if I'm recording myself...
My use of scratch tracks developed in 2011 when I had to make use of my drumming mates in pressured situations because neither live in London anymore. One lives in Zambia ! So quite often, we'd track a number of songs in one sitting, depending on the length of song. On one of those sessions, the song was 20 minutes long so I did a scratch on bass and re~did it later. Another time we managed 13 songs in under 4 hours {they were pretty short} and most of them were scratch bass. The drums are
always keepers. If the double bass is used, I'll do the scratch on bass guitar. The problem there is that sometimes, it sounds so nice and I have to fight with myself to maintain the original plan !
On the long songs, I record in sections so whatever section is being worked on, we'll do it until we're happy with it, then move on to the next bit. I've done sectioning for years so it's second nature to me. Not every long bit is done that way, but most are and even some short ones. There's no real rhyme nor reason though. My main goal is to get the drums or percussion down as the keeper because I know where things are going to go from there. I'm not averse to unplanned sections or happy accidents either. They're some of my favourite bits. If they work.