You're kind of restating the premise of the comment that cited the research paper.
In what appears to have been a carefully run study, under the best circumstances, grass-fed beef provides a tiny fraction of the fatty acid benefits of fish.
In other words: even if grass-fed beef has a better fatty acid profile, "better than corn-fed beef" still doesn't mean "good source of healthful fatty acids"; both grass-fed and corn-fed are poor sources. If you believe you need a better fatty acid profile in your diet, take fish oil tablets or eat fish.
I see you've left a multitude of comments in this post going on around the same, yet it seems to my the angle you've taken is that you need more omega 3s, and not for example that, compared to grain-fed beef, if you are going to eat beef, it's qualitatively better, and to me it seems more important that this way you'll get a lot less omega 6 fatty acids, thus eating food with a better fatty acid profile. To supplement O-3 for the purpose of fixing or improving _your_ fatty acid profile (vs. that of the food) well, sure, but it's orthogonal to the quality of grass vs. grain-fed beef. (Edited last sentence)
In what appears to have been a carefully run study, under the best circumstances, grass-fed beef provides a tiny fraction of the fatty acid benefits of fish.
In other words: even if grass-fed beef has a better fatty acid profile, "better than corn-fed beef" still doesn't mean "good source of healthful fatty acids"; both grass-fed and corn-fed are poor sources. If you believe you need a better fatty acid profile in your diet, take fish oil tablets or eat fish.