Reading the book this picture >>25587 was taken from (De rebus bellicis, written by anon in the 4th century) I noticed the Romans had the same idea as OP. Here's the relevant passage (pic related, it was an illustrated book):
>Expositio currodrepani
>Huiusmodi pugnacis vehiculi genus, quod armis praeter morem videtur instructum, repperit Parthicae pugnae necessitas.
>Sed hoc singulis bene munitis invecti equis duo viri vestitu et armis <e> ferro diligenter muniti citato cursu in pugnam rapiunt; cuius posterior supra currum pars cultris in ordinem extantibus communitur, videlicet ne facilis a tergo cuiquam praebeatur ascensus.
>Falces vero acutissimae axibus eiusdem currus aptantur, in lateribus suis ansulas habentes, quibus innexi funes pro arbitrio duorum equitum laxati quidem explicant, repressi autem erigunt falces.
>Qualia vero huiusmodi machinae funera hostibus immittant vel quas turbatis ordinibus strages efficiant, dicent melius qui usu bella cognoscunt.
Translation pro simplicibus :^)
>Description of the currodrepanus [= scythed chariot]
>The needs of the war against Parthians* made necessary the creation of this kind of combat vehicle, that may seem armed way too heavily.
>Two men, riding armored steeds and fully equipped with iron armors and weapons drive it into the fray at full speed; its rear is fitted with a row of jutting blades, clearly to make it difficult for anyone to climb on it from behind.
>The chariot's axle is equipped with sharp scythes, perforated on the sides and tied by ropes: pulling or loosening them the riders can raise or spread out the blades.
>Whoever has direct experience of war can explain better than me the destruction wrought by such devices among the enemies and the slaughter inflicted upon the disordered ranks.
*At the time of writing, Post too long. Click here to view the full text.