There is a difference in recoil and leaving out the LE ammo there is enough difference in the trajectories of the common factory loads to give it some consideration.
PS. I did go to the Hdy site and had a look at the LE specs for both.
444 Marlin
Energy 100 yards 2285 ftlb Trajectory 100 yards +3"
200 " 1606 ftlb 200 yards -1.4"
300 " 1120 ftlb 300 yards -18.6"
45-70 Govt
Energy 100 yards 2158 ftlb Trajectory 100 yards + 3"
200 " 1516 ftlb 200 yards -4.1"
300 " 1083 ftlb 300 yards -27.8" !!!
I don't think the .444 Marlin has any reason to hide in shame here.
Buffalo Bore loads the 300 grain Speer UniCor hollow point to 2350 fps in the 45-70. Not much difference in trajectory.
45-70 Govt
Energy 100 yards 2544 ftlb Trajectory 100 yards + 3"
200 " 1719 ftlb 200 yards -1.75"
300 " 1170 ftlb 300 yards -20.1"
Now that the LEVERevolution bullets are available as components the 45-70 can be reloaded with them.
45-70 Govt
Energy 100 yards 2569 ftlb Trajectory 100 yards + 3"
200 " 1813 ftlb 200 yards -2.2"
300 " 1278 ftlb 300 yards -21.3"
Not much difference in trajectory, significant difference in power.
If Hornady made a LEVERevolution bullet for the 45-70 that had a similar sectional density as the 265 grain bullet for the 444 Marlin, such as a .458" 300 grain LEVERevolution bullet, when loaded to their potential, you would see similar trajectories and significantly more power with the 45-70.
I wouldn't say either the 444 Marlin or the 45-70 Gov't are better than one another, they're just different. No animal well hit with either the 444 Marlin or 45-70 Gov't with an appropriate bullet from an appropriate load will know the difference.
Both the 444 Marlin and 45-70 Gov't are alive and well. I can't wait to get a 444 Marlin again.