TLDR; When considering veganism why isn't the trade-off between the welfare of the farmed animals and the wild animals the farm replaces considered? 

Disclaimer: Medium term listener, first time poster, and definitely non-expert in moral philosophy or ethics.

When considering the veganism in with respect to animal suffering (for now ignoring the climate, land use, efficiency etc) the debate is rarely set out in terms that makes sense to me.

Using the example of the welfare of the animals involved in egg farming, to me the intuitive, consequentialist, analysis is to trade-off:

• The reduction (or increase) in welfare of the chickens not existing  vs:
• The change in welfare of the animals that would habitat the land use given up by a the chicken farm if it were abandoned, less whatever land is used to farm the protein I replace eggs with.

However there doesn't seem to be much in the way of analysis or debate in this space, which makes me question whether I am missing something fundamental.

On the contrary:

• https://foodimpacts.org/ implies the difference between cage-free and caged eggs is relatively small, even only welfare considered, and does not trade-off against any wild animal replacement*
• http://hamandeggonomics.blogspot.com/2009/08/free-range-egg-production.html has only a relatively small amount on free-range eggs
•  https://longtermrisk.org/the-importance-of-wild-animal-suffering/ very briefly alludes to this trade off but does not include it on its research agenda.

So instead, with limited guidance, I perform a subjective analysis, namely : "do I think its more likely than not that some free-range** chickens have better quality of life than the wild animals they replace".  

My observation is: 

• Free-range chickens are allowed to exhibit natural behaviours and are gifted a few luxuries beside : housing/ constant supply of food/ (imperfect) protection from predators / (limited) treatment for disease and a death likely to be quicker than in the wild. 
• Wild animals- they get the natural behaviours minus the luxuries

So I conclude that eating free-range eggs is net positive, in ethical terms.

But that conclusion appears to put me at odds with the much of the EA community so presumably my analysis is flawed.

Ways I could be wrong:

• Judging wild animal suffering is hard. So safer just to stay off the eggs. Counter: "Hard" doesnt normally stop the debate in EA..
• "Free-range" has a vague definition so its hard to analyse. Counter: as above
• I have not considered the number of wild animals replaced by a chicken farm - and is likely nWild > nChickens
• The climate and land use arguments are big enough to justify veganism without getting into the weeds of suffering trade-offs. Counter: Foodimpacts.org suggests there is interest in trading off climate and suffering
• Caged eggs are by far the more numerous in the US. Counter: Not in europe, and caging farm animals will be banned in 2027.
• Any number of other reasons... 

*This is a unfair- it is not the point of the tool, and 1 person questioned this in the thread in which was posted. But the fact it was only 1 is my point, and the author of the data it was based on didn't seem to interested in the caged/non-caged distinction either.

**The free-range descriptor is obviously important here, but more often than not the comparison is to caged animals in EA forums. Why? Surely most EAer's considering veganism already eat free-range meat & dairy?