The issue with that sort of artificial difficulty is that IS themselves tend to give away a lot of blessings per map rotation in the gardens.
They aren't that hard, imo, cleared every one of those maps first try.
I'm not familiar with many mobile games, but IS definitely seems generous to the players. They give away quite a lot of free stuff.
I managed to beat them all as well, though I have a lot of strong units to cover all the different types.