I realize you want it to do both weapons in hands probably in full graphics but I believe if you put fast graphics on it does exactly that without ever holstering your weapon.
What does fast graphics exactly do when turned on lol. Turned it on to try and see what the difference is between having it on and off but I couldn’t see any ._. I’ve always played on maxed graphics
Some games have 2 different textures/models for things, one for close range(high poly/quality), and one for far away(low poly/quality). The far away ones are ment to look awful to save power/speed, and you probably wont even notice it from a distance. I dont think celtic heroes does this, but it does(or at least did) have several versions of some graphics for different devices(to help lower end ones run the game). If I remember right, fast graphics swapped all multioption textures/animations with their lowest quality ones to help make the game run faster.
I just booted up the game to test it out, and fast graphics did revert my axe stance to the old style, but I didn't notice much else. I also tried fast terrain, which removed some of the hay on the ground by the auction house. I think fast graphics is in a half broken state, it probably wasn't updated/supported for some time, either by the extra work it would require(downscaling the textures and copying them, along with coding it in), or a lack of interest/demand(most newer phones run ch fine).
Heres some old pictures of mine from when I tried to play the new engine on my ipod 4(might have had fast graphics on).