As you can see, there a re a lot of different ways to approach this, depending on your skills, tools, and general approach. Heck, you COULD rough out the limbs, then lash them both to a thick stick for a handle.
If the splice has to hold the whole thing, then, I say make it a bit longer (3-4") leave that handle thick as you can, etc.. But, Marc is right too; the more extensive and well-cut the splice the shorter it can be. A fishtail is good, a Z-splice is better, and a W splice even better, but by then I'm running out of room.
Socketing into a length of pipe costs you almost no length, although I like to make a slight scarf cut on each so they settle together and don't rotate.
if your handle section is kind of long and you plan on adding a riser block and overlays, you still need a good splice, but it can often be shorter or just a diagonal slash running side to side, then cover.
If you back it, lots of options open up.
One thing that DIDN'T work for me..... I often do simple front to back scarfs. These need to be pretty long. I like 4", and the fades need to be well outside where the splice ends, and the splice needs to be glued and wrapped like mad, tightly with small string or wire so you get a lot of rotations and it all stays really snug. If I make the splice short, or tried to glue on a thickened for the handle, I can't get that riser to stay put no matter how I glue or wrap it. The short splice allows for too much shift, and a tiny flex through the handle works the whole thing apart. Just mentioned it because you said it was a board.
