Bugs or working as intended?

[Frosted Flake]

Had 2 unfortunate commander losses and wondering if they are meant to be the way they are. The first was as arco, free hero is bonus seiging but not defending - unlike the engineer units you purchase. I should have paid closer attention and it set me back but I am thinking its an error he should be bonus both ways. The second is my Kraken died because he couldnt retreat, all the other commanders ran to an adjacent province(land) but he did not. This in spite of having the amulet of the fish and could have moved to the province. This is a bug or just an awful screw.

[Ozymandias]

I have seen mention of commanders wearing fish amulets still not considering land provinces as valid retreat routes in the bug thread. As far as that hero of arco's, did his description mention expert crafting of siege weapons, but nothing about defending? The two bonii are not required to be together.