It's not a matter of what round, it's where in the round. The best 4-3 defensive ends go very early in the 1st round. They simply don't drop to the end of the round. However, you can get some of the best 3-4 OLB's and DE's late in the 1st round. In addition, the talent pool for the 3-4 is much larger than the talent pool for the 4-3.
Let's face it, the key to having a good/great 4-3 is to have a pair of very good DE's. Unless we pull a couple of blockbuster moves, we're simply not going to be able to obtain that in the next several years.
I do not subscribe to the idea that the 3-4 > 4-3. However, I believe that in order to have a "stout" 4-3 defense, you need some top talent at the defensive end positions. For the past several years, we've had half of that equation in the form of John Abraham. However, we have all seen that with only half of that equation, we just don't get enough pressure. If we want to improve the defense with Abraham gone, that would require us finding the two most significant pieces in the 4-3, and it's one of the hardest positions in the NFL to fill.
I actually believe that the 4-3, provided you have the talent, is the superior front. However, getting the talent to have a dominant 4-3 is very hard to do. At this time, because of our recent success, we simply do not have the resources to build that kind of line. We would be better off re-tooling to a 3-4 for as long as we have Matt Ryan. (because as long as we have Matt Ryan, we will continue to draft at the bottom of the round)
It seems you've concluded that because the Falcons will be picking towards the latter half of Round 1 every year, it'll be harder to get premium talent on defense.
I would agree with you. Most of the top-level pass rushers in the NFL today were formerly Top 15 picks in the draft. And it is a true that most of the good front 7 players that have been drafted in the latter half of Round (picks 16-32) over the past 7 or 8 years have played in 3-4 schemes.
I wouldn't automatically assume that it is any easier to build a top-level 3-4 defense based off that fact. Very few of those 3-4 successes are the type of player you seem to be talking about. Because the two main components: edge pressure and interior pressure work the same in both defenses. Finding J.J. Watt isn't any easier than finding Ndamukong Suh, and the same works for Aldon Smith and Chris Long.
This topic is exactly why I pushed for the Falcons to pursue Mario Williams last off-season, because they would have limited access to elite pass rushers in the foreseeable future, and thus needed to take advantage of a rare talent like Williams hitting the open market similar to what the Bears did with Julius Peppers. But that access to premium pass rushers is just as limited if they were running a 3-4 as well.
The other facts is that wehn you look at most of the mid-round (3 thru 5) talent that has gone onto become successful NFL pass rushers, nearly all of them are 4-3 guys. Very few impact 3-4 edge rushers have been taken past the 2nd round over the past 7-8 drafts. So if the Falcons are going to be forced to rely on non-1st round talent to build up a good defense, then it would then make more sense to stick with a 4-3.
And let me reiterate, I'm not against the Falcons moving to a 3-4 eventually. Where they are in 2014 and 2015 may be drastically different than where they are today. And then it could make perfect sense to switch schemes. I just don't buy into the belief that the Falcons need to switch, nor do I believe they need to start beginning the transition.
The bottom line is that the Falcons need more playmakers up front. Preferably they will be players that have scheme versatility that can play in either scheme.