They're cheaper (especially due to them not having iron costs) and it's only 1 attack/defense point.
Only problem I'm seeing is that attackers will start using droids exclusively.
One of the fun parts of attacking was that you could completely wreck another attacker's ground if he had no sols, because droids sucked that badly in defending. It's like a strategic game of what droid:sol ratio to make. Now that is all gone, due to soldiers, NW for NW, are just inferior to droids.
Also I fair that, as Lee said, this change hurts preset races that do not have access to droids a bit too hard. It may just be that little bit easier for attackers to run through a banker's ground than it has been in the past, to make these preset races sitting ducks, unless they are willing to pay a shitton of upkeep to maintain huge soldier counts.
Maar doodslaan deed hij niet, want tussen droom en daad,
Staan wetten in de weg en praktische bezwaren,
En ook weemoedigheid, die niemand kan verklaren,
En die des avonds komt, wanneer men slapen gaat.