Better for EE, as you can attack (more successfully) against the common 1 atk build hansel. Worse for OSW, as you have to drop 2 buildings (doubling your losses) if you like to fight as a pure spy, also reducing your main attack, spies. OmegaLSA
You can't do **** to a pure spy, they have nothing to lose and can do some decent damage to the enemy.
I suppose if you have no allies, but if you have no allies then what do you care, as hansel you can pin troops and pull top steal with out becoming an osf
1 attack building or 10, does not matter because game mechanics treat them the same as long as you have less than 25 percent of your explored lands with troop buildings. Trust me I've tested it. Only difference between 1 troop build hansels and the rest is that the 1 building type typically turn into pure spy if they get stripped.