I find that even my 20mm scopes, Leupold VX-II 1x4x20mm, Weaver V-3 1x3x20 and Nikon Monarch 1.5x4.5x20mm are bright enough that if I can see a coyote coming with my bare eye I can see him in the scope for a shot. The only problem I've had is with too fine a retical and not being able to see the crosshair in low light conditions.
Having a larger objective only lets the scope be brighter at a higher power and it isn't a large increase. A 32mm scope at 5x will be about as bright as a 50mm scope at 7x. Quality of glass and coatings will enhance brightness more than objective size.
FOV has very little to do with objective size or tube diameter. You can verify that on any of the spec sheets for scopes.
Target aquisition has alot to do with reticles. Busy reticles like BDC and others that have to get alot of information in front of your eye with be harder to use on moving targets or in field positions. A heavy duplex or German #4 will be easier to use in low light and moving targets. That's why most dangerous bame scopes have large FOV and heavy reticles, most of them have 20mm or 24mm objectives.