How many heroes can a map support

I'm trying to make a map where every unit is a hero basically. They can't be revived but I'm assuming the game still keeps track of them since they have stats skills and stuff. Any rough ideas on how many heroes there can be total throughout the play of the map without it slowing down (if at all)?

You could remove killed heroes, then they'd take up no more data. The additional memory cost of heroes from units would be negligable.

do you don't know ? the limit is 7. for each player the 8,9... will be unusable after somw time (they are some kind removed) but i set hero dissapite time to some large the hero model will be keeped but you can't ressurect etc. this unit (hero) so no more than 7 heroes. i mean really functionaly heroes.

Oh yeah, I forgot about the remove unit function. Thanks Captain Griffen. I'll try it out.

And Toadcop, well for the map, I don't really need fully functional heroes. Just need a lot of them.