To be honest, I'm kind of a turtle myself...

Nevertheless with the game such as it is now (sacking benefits and all), in a PvP campaign, I think the hare would steamroller the turtle, as long as military victories followed its path of conquest... The sheer impact of the sacking cash flow is something that cannot be matched in "turtling"...

Moreover, blitzing has no need for diplomats, merchants and just barely needs assassins or spies (only to soften town/castle resistance) so the blitzer is able to concentrate his expenses on units and mainly mercs, thus gaining a head start as in the begining mercs are so much more powerful than starting units (think Merc Xbow... )...

So I think for once the hare will win the race...

Just my ...