I'm afraid this one doesn't really work for me Dan; the double-bit and the shale he's laying on both say to me anything but, 'soft, gentle, etc'. I think a diffused speedlight low and right would have improved the overall image significantly.
For me it's the pose of him lying on his back being photographed from above with the axe being held close to his heart and the expression that translate the softness/ vulnerability, and I like the contrast it has between the vulnerable pose and the hardness of the setting and prop. This is simply what I see though; I'm not trying to disprove or say that your point of view has not merit.
I'm trying to avoid using my speedlite as much as possible these days, especially for personal work. Maybe a reflector for fill would be a decent alternative, and using a tripod so I can get slower shutter speed and aperture?
why on earth are you trying to avoid using a speedlight?!? thats crazy talk man! flash is your friend! you get far more control with a flash than with a reflector. you can do MORE with a flash than you can with a reflector. plus, with a flash, you aren't completely reliant on how much "natural light" is in the particular spot you want to shoot in.
If you already know how to use a flash on and off camera, use it! you have more directional control with a flash, you can soften light with a flash, and you can offset mixed lighting with a flash.
anyway, if you are really set on handicapping yourself for theses shots, yes, a reflector might help a little, depending on how much light is actually getting through there to reflect. you might also try using a tripod to get your shutter speed lower. the only disadvantage there is you cant get as high up. best option? off camera flash and stand on a ladder. dont get all hung up on "artificial" light. light is light. use what you can to get the best result. all light sources look "natural" when used correctly. lighting with a flash will also let you stop down your lens a bit for more DOF.
your only options are: add more light, slower shutter speed, or higher ISO.
best option for lighting is a flash, tripod for slower shutter speed, ISO you said you were already maxed on.