Rules/guidelines aside here. Totally hypothetical.
This is very much a "what if?" thread.
'Viable strategy' here depends what your intended outcome is...some play to win, others to gain points. If your intention is to piss other players off, your viable strategy might well be quite radical.
Deadbeating in a singles game? I can't see this ever being beneficial. Maybe if you're in an assassin trench warfare game, and somebody is coming at you but has a three region path to cross (ergo takes three turns to take with trench warfare, giving you time to deadbeat) in order to eliminate you. But if you deadbeat, maybe a higher ranked player will win instead, and you will lose fewer points. This is the first instance of intended outcomes differing as I mentioned above. Let's assume you're going to lose the game either way. Your aim is to lose fewer points...this is a maybe. However, this example is really, really stretching the bounds of what's possible.
Also, am I correct in assuming that if your target in an assassin game deadbeats, you inherit his target? That's kinda important in this example.
But deadbeating in team games?
Let's first look at region-count bonuses. You and your partner in a doubles game both have 11 regions for 3 troops each. However, you deadbeat. Your partner has 22 regions for 7 troops. Interesting.
However, I don't think this is ever viable in sequential games, as your partner loses a huge advantage in the turn order. Between each of your partner's turns (after you've deadbeated), the opposing team can deploy twice and there's nothing you can do to intercept that.
In freestyle team games? Well, maybe. Not only does one player inherit the teammate's region-count bonus, but he might also swallow up and claim a bonus which was split between the team before. And there's no problem with the turn-order if one assumes that you would be playing concurrently anyway. Well, that said, there is an important benefit of having more than one player on a team taking a turn: when you have deployed your troops to break a bonus on the other side of the map, you happen to fall short at the last region. Your teammate, turn started and waiting to deploy, can drop some troops on you to finish the job. This can't be achieved solo, because once you've deployed...you've deploy. Unless you eliminate somebody and re-cash some spoils, but whatever.
However, I feel that in 99% of situations with potential for tactical deadbeating, the benefits of just taking those 3 extra turns and doing damage with them outweighs the benefits described above. This is true especially in team games, as autodeploys and deferred troops aren't inherited by the teammate.
And some other stuff. Zzzzzzzzz...