Heroes and Drops

If I went by myself in a party with 3 heroes, and started to farm, do the heroes take as much drops as henchmen or what?

Heroes and henchman, will take drops from you if they are helping you farm. If however you kill all the mobs around say a green dropping boss then flag them so when your solo killing the boss and their names are greyed out. You will get 100% of the drop.

Basically yes they take drops unless your doing green farming like the above mentioned way.

Ahh good old cleavage farming

An easy way to show is to pick up some gold when you farm with heroes.
"Party shares x gold"