This depends, again, on your goal. Is your goal "complete a comic?" then yes! wasting time on extra rendering is pointless, and doesn't serve your goal. Is your goal "complete a beautifully rendered comic?" then no, skimping on the rendering to finish a comic more quickly won't get you closer to your goal.
"Work smarter" is a simple catchphrase that's easy to say, but it encompasses a lot of ideas, and I think it can be more helpful sometimes to consider those ideas -- figuring out what your goals are, and figuring out how to prioritise the most important goals, and determining the best way to reach the goals that are most important to you. Many of us have lots of goals -- communicate a story, make a nice-looking comic, grow our readership, grow the engagement of the readership we have, etc. How you, personally, prioritise those goals is going to determine what "working smarter" looks like for you, which sacrifices are "smart," and which elements of hard work are essential.
I mean, if you work very hard, and then get a lucky break, then what did you do to reach that position? You worked hard. You didn't do anything to make the lucky break happen, but your hard work was what enabled you to take advantage of the lucky break.
If someone asks me "how do I get a following on tumblr," I'm going to talk about how often I post and the kinds of things I post -- I'm going to tell them things that I did that contributed to getting a following. I'm not going to just say, "well, you have to get reblogged by the right person in the right fandom at the right time," -- because that'll help, but if you just sit around waiting for that to happen, it isn't going to happen. Instead, I'm going to direct them to things they can do to help them reach that point where they can get reblogged by the right person.
That said, it does feel disingenuous to ignore your privilege and fortune when someone asks you how you made it where you are -- I think it's good to make those disclaimers, and more folks should! But even when those things are acknowledged, I think the focus is still going to be on things you did moreso than things that happened to you.
I don't quite agree with this! A lot of times "who you know" is the source of an opportunity -- but you can't take advantage of those opportunities without a lot of hard work. You can't make those connections without a lot of hard work. It's easy to see someone get an opportunity because of their connections, and think "I could never get there without that connection, no matter how hard i work" and decide that must mean that connections matter more than hard work...... but imo the truth is that (a) they're connected and (b) having connections doesn't make hard work less relevant. I know there are exceptions, but every well-connected professional I know is also an extremely dedicated hard worker, and I don't think it's wise to count on being that one exception that can get away with lots of connections and little work.