You can never have too many top 6 players. What you need to do it make sure that players are multi-faceted if they end up on the 3rd line. Right now, the 3rd line wingers are looking like Kravtsov and Blais. Kravtsov has the skill to join the top 6. Blais has the sandpaper to play as a tweener. His last year in St. Louis he was producing like a top 6 forward, just not getting the ice time to put up the raw totals. Downside was he shot 25% and has never done that before. We did see he has skill too when he was healthy. Good news is that he's going to have a normal offseason to train. Should be fully healthy already.
Where the team is lacking is someone to jump into the top 6 as a center if needed. If they re-sign Copp, I'd love for them to use him in a 3C role while letting Chytil run with Panarin, at least to start. A line of Blais-Copp-Kravtsov has potential. Line with size and skating. If you want to roll more of a matchup line, you could put Kakko there and have Kravtsov move up with Chytil and Panarin to go pure offense with that line. If Copp is not the guy, it makes things more difficult IMO.
The last part is making sure that the 4th line is not just there to fill in 8 minutes of ice time. Goodrow is a perfect start to that. Hunt can be part of that, but as the 13th forward. Reaves is not part of that, but I can understand having him around as a part time player. You need to find two 4th liners in free agency or promoted from within. Motte can be one of those, and hopefully that report from Mollie Walker is accurate. I'd prefer the other is a center than can play on the wing if needed, especially with their down the middle depth in the system.