This is an easy projection
Our future forward core is on average age:
Mantha, 24
Betuzzi, 24
Athanasiou, 24
Larkin, 22
Hirose, 22
Svechnikov, 22
Rasmussen, 20
Zadina, 19
Veleno, 19
That's the offensive TOP9 (10 players, some will fail, some will be dropped out because of future picks) core already. Average age of that is:
~21.8 years
Defence:
Bowey, 24
Cholowski, 21
Hronek, 21
Lindström, 20
McIsaac, 19
That's the defensive kid core. Not sure about Bowey being anymore than 3rd pair guy, than Average age from defensive kid core is:
21.0 years.
Offence: 21.8 years_avg
Defence: 21.0 years_avg
Offence with Cozens/Dach/Turcotte/Krebs: 21.3y_avg
Defence with Byram: 20.0 years
So our offence kid core is almost year older than defensive kid core. Getting a guy like Byram from next draft, will push this gap even bigger, on wrong direction.
Defence should be 2-3 years older than offensive core on a balanced team, to peak at same time. Because defencemen will take time to develop oon reliable level, more than forwards. It's just a law on hockey.
If you draft Byram, him being currently 17-year old and almost a decade away from his prime, would push that Defensive kid core average to 20.0. So difference to forward core would grow to almost 2 years.
That's hos many bad teams are built. Strong offence and young mistake-making defence. High-scoring game. Will lead to high foward caphits, because of high-scoring games.
Good cap-controlled are build balanced, because good and not in-experienced defence will keep scoring totals low. Then forward caphits won't accelerate on your hands. That's how long-term winning teams should be built in a cap world.
Yzerman did built Tampa quite perfect way on age distribution. And all the time he favored a veteran defence. Hedman is 28 and that defence core in general is a lot older and experienced, than their offensive core. Kucherov is 25 and on his peak. Hedman is 28 and on his peak. Stamkos has already regressed and is the 2nd best forward at 29 year old. That haven't won anything but it's still the best core which just need some finetuning for playoff hockey, against different styled teams.
In our case, when Byram is "Hedman", it's 11 years after, and that defensive core would be 28 on average 8 years after, then Byram is 25.
So if we draft Byram now to be our 1st D, we should expect that when he and our team is in prime, our forward core is some guys of drafts 2021-24 coming. Some current undrafted 13-15-year olds. If we want to wait that long. Larkin would be 32-year old, Mantha/Bertuzzi 34-olds. Regressing already. Totally mismatched primes.
But we won't have to wait that long, because Yzerman is best at his job. We can keep drafting forwards and trade for a proven defencemen, because those are available on the market all the time. That's the Plan A. Byram's could be Plan B, if he is there.
Drouin for Sergachev, even some matured prospects are available. Karlsson is there, Hamonic was traded, Trouba-rumors, Faulk-rumors. Seth Jones was traded, when Columbus had a forward logjam. They let their 1st line center go and drafted a new kid Dubois, because forward kids will reach their potentials usually faster. Now Jones-prime matches better with Dubois-prime than Werenski would have matched with Johansen-prime. Burns was traded, Suter left Nashville, etc. Those things happen, for various reasons. The market is always there. Just wait for the right fish and Yzerman pulls the trigger.
Trouba could be that fish.
So offence without Byram, with new 2019 center forward + a trade where Athanasiou and Cholowski go for Trouba:
Offence: 21.8 years_avg
Offence with Cozens/Dach/Turcotte/Krebs and without Athanasiou: 21.02 years_avg
Defence with Trouba and without Cholowski/Byram: 21.83 years_avg
With those groups future defence core would be 0.81 years older than offense. Then we would be on the right way to right balance.