Yep, with the high str you usually have as thrower, one or two blocks + left to right will catch many people off guard and do some nasty damage. You can also use them to kill shields in melee and then retreat back and throw. You should always keep 2 as reserve, so you can throw one when he gets outside melee range. If you are good at blocking or have a shield you can walk over during the fight and pick it up again.
I don't really see why you'd want to use the francisca, any serious thrower has PT higher than the heavy axe requires. For pure melee they are just weaker than normal 1h in all aspects though.