Yeah, I'm down with all of that. Honestly, I don't think any of Kill 'em All focused on having entire pieces being written as competent, respected musical pieces. I think they just wanted to make awesome, visceral music that got metal dicks hard and, because Cliff and James were such good writers in the first place, the album came off as a very polished debut given the era, their budget, the relative infancy of its genre, and how early in the band's career it was.
RTL is where you can see the beginning of James' grand vision coming along as it was heavily guided (I assume) by Cliff's melodic mastery. The opening track's intro is a humongous middle finger to metal purism, RTL's solo section is a perfect example of excess in the name of overly ambitious grandiosity (I still like it but modern day folks whom seem to consider themselves experts sure aren't shy about knocking it), Fade is a gem for the ages and a crowning achievement in 80s Metallica's ability to use dynamics to their seeming fullest potential, Creeping Death showed they could have a steamrolling ass kicker that had sophisticated structure and deft flow, and Ktulu does great justice to H.P. Lovecraft's short story without having a single lyric.
Longwinded as the previous paragraph is, I typed it out to point out how RTL seems to have an intentional emphasis on quality writing and composition whereas KEA is just a very enjoyable and well-executed debut without such endeavors so it's pointless to knock Anesthesia for not being a proper song when virtually every popular band has made a short song, instrumental or not, that falls outside of how the average fan would classify the majority of that band's discography.