Who’s the more effective leader there?
I forgot to answer this. In this situation, yes the GSA is a better leader, I guess. But I would hardly call that leadership. And what about when the cashier is standing around doing nothing and the GSA doesn't know what to do? That's when the ETL leads. They can teach the GSA how to get more out of that cashier. The ETL can either approach the cashier directly and have the GSA observe, or the ETL can challenge the GSA to approach the GSA on their own (with or without the ETL's supervision). This is where the real leadership comes in. Sure, it would be nice if the ETL knew everything on day 1, but they don't need to know everything - that's what their team is for. What they need to know is how to motivate their team. How to improve their team. And it helps if they know the workcenter, but it's even better to know about human nature.
I guess the majority of this discussion comes down to this question: which skills are harder to learn, workcenter-specific stuff or leadership stuff? Most of the stuff we learn at Target doesn't take much. It takes a fucking hell of a lot of work ethic to get everything done, but come on, how much do you actually use your mind in most workcenters? I have to actively look for ways to keep myself entertained because it's mostly just going through the same motions that I could teach a 10 year old.
Leadership skills generally take a lot more practice because every person and every situation is unique. My approach to lead one team member might be different from how I approach another one, but scanning a REDcard application is going to be the same.
Lets take one new TL (person A) who has never worked for Target, but was a great leader at another job (maybe food service, so not quite retail but in a semi-related field). Then another TL (B) who was a fantastic TM but that's it, no leadership skills (or very little). After 1 year in the job, I think person A would likely be able to learn the job and the job of the people below them. Most of the training for that stuff takes like a week or less for the TMs to learn, so I'm pretty sure they can learn it in a year. But person B... they could turn out to be a fantastic leader, but I think they would still have a lot to learn even after a full year.
A lot of this is based on my own experience. I've seen tons of TLs who are great at their job and terrible leaders. They were great TMs, but had no leadership skills and now they're ending up doing 120% of the work that they're expected to do because each of their team members is doing only 80% of what they should be doing. This TL is trying to pick up the slack of 10 TMs and is working their fucking ass off, but it's still not enough. I appreciate how hard I see them work, but their workcenter sucks. Their hard work may motivate me, but it doesn't motivate everyone.
I also know that even though I've mastered every workcenter I've worked in and raised the bar, I can still be a way better leader. I was in a few different leadership positions (GSA, TL, SrTL) over the course of 6 years and still have a lot to learn. But I can't be a better cart attendant - learned it in a few minutes and mastered it in a week. I can't be a better service desk TM (basic training in a day, learned more over weeks, mastered it in a couple months). Same with Food Ave, Starbucks, sales floor, cash office. And I bet I could learn logistics positions in similar time frames. But being a leader? Yeah, like I said, 6 years and still learning. I doubt I'll ever truly master it the way I have with these workcenters because it's far too complex.
), I was empowering them. I respected them. I encouraged them. I recognized them verbally and thru YouCards. I got in the "trenches" w/ them. They were proud. I was honored that they connected w/ me and trusted me. Even though I was "green" to Target; the Team quickly treated me as their Leader. And, while I don't technically "lead" the Team now...... we still have a great unity of trust and collaboration to make things better. 
