Hey Ilan,
That is a good question. I believe we discussed it somewhere in the Forum…
I personally prefer to trade many EAs in one account.
For example, a good strategy for beginners is to use 0.01 lots and just add to the account more and better EAs.
So if you start with 1000 dollars account you can easily begin with 10 EA. Then you can just add another EAs with 0.01 and you will not have issues with the margin.
If you have 5k account it is fine to trade even with 100 EAs.
This way you will achieve really great risk diversification.