its not a bad idea, but i just don't see the point and here is why.
Go have a look at your leagues draft history - and look in round 1.
Look at the preference that everyone got. 99% of the time, people got their 1st, 2nd or 3rd preference in the first round.
If I look at my league, last seasons draft, only 3 teams DIDNT get their first preference (they got their 2nd or 3rd).
The previous season - 6 teams didnt get their 1st preference, but they got their 2nd and 3rd (and the person drafting last, got their 4th preference)
Season 25 - only 2 teams didn't get their first preference, but they got their 2nd.
Point im trying to make - is that teams generally get their first preference anyways - SO even if you had a draft lottery, it isnt going to change anything, the team that picks first/2nd, 3rd, 4th, last, is still very very likely to get their first preference.
So why have a lottery? If you going to pick 5th and still get your 1st preference, then who cares if you pick 5th, or 1st, or 2nd, or 6th.
Make sense?