You don't tank tactically, but you can tank strategically and structurally, which is basically saying you tank in the off the field (sign cheaper, less talented (at the time) players, don't sign other players, build your drafts according to a longer plan than the immediate needs scenario, etc.
This is the only way to build a consistent winner. Building a young, dominant offensive line, that goes three deep across the board so the 1st string can grow and develop a cohesive unit - to the point where they can finish each-other's sentences - and then putting a Franchise talent at QB once that Oline has had a year to start that growth seems like the best way to move forward. Remember, you've already got Laremy Tunsil in place and playing at an elite level at LT. That's a BIG hurdle in the rebuild plan. You can build around Laremy and it may cut some time off of the Oline rebuild. It usually takes a few years for the LT to develop.
You can add good players at RB and WR, in year two and maybe add the new prototype TE that the best NFL offenses have (Kelcie, Gronkowski, Ertz) - too big for a db to cover, too fast for a LB/S to cover and too strong for the DE to be able to shed easily in the running game - in year three or four. Remember, we already have some good young players at this spot - Drake and Ballage at RB and Stills, Wilson and Grant at WR. Might be nice to add an eventual tall #1 receiver (to fill the role Parker was supposed to play).
Once the offense is built, you can add smaller pieces, and your running game will be able to help your young and learning defense. At this point you can take the same approach now with your defense. Year three in the draft is when you start stocking your team with Defensive linemen. The new direction for defenses now is to find interior pass rushers. So you take the same approach that you took when building your offensive line only they don't need to finish each-other's sentences. Unlike the offensive line, you just need disruptors. If you have four disruptors up front, that is enough. Then you get an instinctive, run-to-the-football ILB to captain the defense. One that not only is instinctive, but who understands the purpose of the particular defensive scheme you're running, and is unafraid/no hesitation acting on that instinct.
We've already drafted the next three components of the plan - A shut down corner (Xavien Howard), a versatile, intelligent, top athlete (best on team) Free Safety (Minkah Fitzpatrick) and a strong run stopping strong safety who works well with your FS (Reshad Jones). You might say we're in year 2 of a full rebuild.
So in year 4, you can focus on finishing out that defense by getting a couple of cornerbacks who each specialize in a particular type of coverage. One or two that are adequate man on man defenders, and two that are adequate zone defenders. The key being the ability of your two safeties to operate in either coverage type efficiently and on a play-to-play basis. Their ability to have the defensive backs all on the same page on every snap and having everyone in place in those key situations where the defense calls a special play (blitz or coverage switch - m2m to zone and vice versa) before the snap, will determine how effective the defense can be.
Then last but not least, your OLBs (really it's the two OLBs and the weak side ILB). As for the OLBs, you one should be a natural pass rusher, the other should excel in coverage. The weak side ILB should be a run stuffing machine that you can replace on third down with one of those CBs mentioned above.
By year four, your team should be loaded. Draftwise, you're rinsing and repeating each of the processes again. Now you're filling holes that come about as a result of age - especially with that offensive line who has been working together in the trenches for four years now. You're going to have injuries and the occasional defection for more money. You're probably going to have to give your Franchise QB a lucrative extension and your stud CB, FS and ILB on defense are ready for new deals as well.
Add to all of this, a dynamic head coach who commands the respect of his players, and is not so stubborn that he can't adapt to changes that occur strategically and philosophically and coordinators who are hyper sensitive to little things that can doom a team before the ball is snapped. On offense it's things like play tipping (linemen set up in a different stance for run vs. pass), lining up EVERY play with 20 seconds to spare on the play clock (how many times did we see RT get the offense to the line with 4 seconds or less to go - this prevented him from scanning the defense to see what they are doing and it completely nullifies the offense's advantage of surprise because they know the ball is going to be snapped before 0 or it's a penalty so there's no downside to flying off the ball at the zero - how many times were the defensive line in our backfield at the snap? Same thing with the defensive coordinator. It's coaching, noticing those little things the opponent is doing (like consistently snapping the ball at zero etc.) and using that to your advantage.
So if the plan moving forward is something like this, I'm all for it. It means structurally, we'll probably be a poor team - say 3, 4 or 5 wins next year, but in excellent position to be good in 2020 and stay consistently in the 11 - 14 win area thereafter.