Face to face, indeed. But, are they not still a part of His Body? By which I mean, to experencing the union that we see through that dark glass.
Dead believers are in a different category, no longer needing to walk by faith as Christians on earth must.
If you believe, as I think that you do, that Jesus intercedes with the Father, and if "dead believers" (can we say "fully alive Saints") are in face to face union with Him, why could they not also intercede for us?
They would need to be able to receive prayers from innumerable believers simultaneously. The angel that went to Daniel could not come to him for 21 days because he was battling with the Prince of Persia. I am of the opinion that the believers in heaven are similarly still subject to time constraints. We do not acquire divine attributes when we get to heaven.
Only God is outside of time, capable of receiving the prayers of millions of believers simultaneously. Of course Jesus Christ is God, ever making intercession for us at the right hand of the Father. Jesus should be enough, being that He is omniscient, omnipresent and omnipotent. Divine attributes that enable Him to handle all of our needs.
I would add that we are engaged in a spiritual battle here on earth, because Satan is the Prince of this World. I mention this because our fellow believers on earth are currently participating in the battle with us, thus relevant to prayer requests. The believers in heaven are no longer subject to Satan's rule, and are therefore no longer engaged in the battle until Christ's second coming.