We will not know if the deep ball is important until we see the offense they are trying to run. If we run an offense that is similar to the Dallas offense of the mid-90's, then yes it will be important.
In any offense, the important thing is to create mismatches at the point of attack. Most defenses will stop you if they have sufficient personel at the point of attack.
Some offenses focus on spreading the field horizontally, some vertically. In either case, the idea is to give the defensive players responsibility for an area of the field that is away from where you intend to run the play.
Another tactic is to make the defensive players hesitate and be late getting to the point of attack. This can be done by play action passing, misdirection plays, and counter-type runs.
I think a better OL, better play from the WRs, and a more accurate down field passer will lead to an offense very much like the Dallas offense.
With our active FB and TE, and two WRs that can stretch the field, I think we will be much more successful on offense this year. We probably won't have the OL to match Dallas' production, but we should be effective.