I'm play too and i stuck but after my battle is with units who is week or equal strengt with me.
If have no choice i fighting wit units who is more strong then i.
My great units is Cyclops and I have 5. I try to save to no die because is archer and is rare.
Because i search and i fight with troups more week then me i have 8/10 of my 'no-loss' medal
(this is for basis
)
Anyway after any battle i suply my lost units.
God Luck