I totally love the shield decals for my Macedonian Phalangites
These are really excellent transfers and fit the shields perfectly.
Initially they do look a little 'large', but if you follow the instructions about curved or domed shields and you lightly score (roughly across the middle of the transfer), it will rest nicely without too much messing. And seems to then fit bang-on.
Because of the dome, the pre-adhesive side can struggle to stick, so perseverance is needed. If you press them as best you can and let it dry, i find using Micro-Sol really helps smooth out any kinks or none stuck bits you might have.