If this draft becomes deep like the 2003 draft then acquiring more picks would not be a bad decision. In that deep draft there are multiple all-stars, Stanley cup winners in the late first rounds, second rounds and even later.
When you can get someone like Corey Perry at 28th overall that could potentially be the Leafs pick from Nashville this year. Keep the picks and do not use them to trade into the top three unless you can get McDavid.
Dropping down in the top 10 would not be too bad if you can still get another first rounder in the same draft. In 2003, in the 7 to 10 overall ranges you get:
7 - Ryan Suter
8 - Braydon Coburn
9 - Dion Phaneuf
10 - Andrei Kostitsyn or 11 - Jeff Carter
If the Leafs trade with Philadelphia currently in 9th overall and pick up the 26th overall (Tampa Bay's pick) then the Leafs could have picks in 9, 26, and 28-30 overall.
So in 2003 if the Leafs were picking they would give up Tomas Vanek (5th overall) or Milan Michalek (6th overall) and instead would pick up Dion Phaneuf (9th overall) and Brian Boyle (26th overall). The 28th overall pick was Corey Perry, so there could be a chance the Leafs draft a Phaneuf type player 9th overall and Brian Boyle with Perry being used for the Nashville pick at 28/29 overall.
Of course that would be the best-case scenario for trading out of 5/6 for 9/26 overall picks. The draft is a risk, but if the scouts are doing a great job it could be possible to get the more players that can help the team out.
Detroit has been doing this for years trading their late first for more second/third round picks with some success, so the Leafs could consider following this model. It's a tough decision for sure.