Let me directly kick in with my conclusion. No one can beat Hive account@lynncoyle1 in the 2nd curation league, because it would cost you at least 15 hours per week!
She writes an average number of 490 comments per week and 136,590 characters. To do so she of course have to read lots of articles. And that consumes a lot of time. Time most people don't have or are not willing to spend.

If you are a regular reader of my posts you can now decide wheter you continue to read or that you stop after my main conclusion. I came up with the idea to write this post like this, because I personally really hate to read a very long article with basically information that I would have understood within 1 minute.

The introduction: Ashers curation league

Each Sunday Hive account@abh12345 write a post name "the curation" league. This weekly contest contains actually 2 contests. The first one is about getting the highest curation rewards (check out some of my other posts to see how you can win this contest). The second contest is more about engagement. Engagement is all about contributing to Steemit by writing posts, commenting other peoples posts and reacting to comments you receive.

https://steemit.com/engagement/@abh12345/7619qe-the-curation-and-engagement-leagues-sponsored-by-carlgnash-and-paulag

average typing speed of 450 characters per minute

About a decade ago I was able to type with 450 characters per minute. That number was without numbers and capitals. Including capitals and number I was probably somewhere between 300 and 400. I'm quite certain that if you can type that fast, that you belong to the top 3% of quickest typists.
Even if you can type like 400 characters per minute, it will take 341 minutes to type 136,590 characters. Which is about 6 hours. So if you only make it to achieve half that speed, 200 characters per minute you will be typing for 11-12 hours in 1 week to comment as much as Hive account@lynncoyle1 does.

Besides the typing time you also need time to read something to react on. 200 of Hive account@lynnloyle1 comments are replies to replies. Those probably take a bit less time to read compared to a article. Nevertheless it remains difficult to estimate how much time is spend on reading articles. But if you write about 500 comments I would guess you need at least 5 hours, probably even 10-15 hours to read stuff. So I estimate it takes at least 15-16 hours to make any chance to win the 2nd curation league. And that's based on the condition that you can type pretty fast.

average time per comment

Let's take a different approach. And estimate the average time it takes to write 1 comment. That means most of the time you need to read a post, a comment or a reply to your comment. And then you have to write a comment with an average length of 136,590/490=279 characters. Writing such a comment will last at least 1 minute. Let's assume it takes another minute to read somehting. Then it will take 2 minutes per comment is 980 minutes in total. So with these assumptions it will take 16 hours per week to win the 2nd curation league.

Can you really do nothing else to beat Hive account@lynncoyle1?

Based on my analysis you know that you can win by just spending a full work week (40 hours) on Steemit. And comment like hell! Your reward will probably be at least 10+ SBD. 3 SBD prize money from the contest and 7+ SBD should be possible if you write such a huge number of comments.

As I don't have this much time, I wonder if there is any other possibility?
I think there is at least one...........