Here are some technical (numerical) details, but as MP said, it really depends on what works for you. There are at least 3 differences I can think of between your road bike and your MTB which will make it unlikely that you'd want the same gearing on them. (1) They have different wheel sizes, (2) the MTB is much heavier than the road bike, and (3) you ride in a somewhat different position. Here is the numerical stuff:

Gear ratio (inches) = (chainring teeth)/(cog teeth)*(wheel diameter)

Your road bike has 700c wheels (27.56 inch diameter). With your low gear of 30/26, your gear ratio becomes 31.8 inches.

Your MTB has 26 inch wheels. Assuming a low gear of 22/30, your gear ratio is 19. That is, for every revolution of the crank in your lowest respective gears, your MTB goes 19*pi (=60) inches and your road bike goes 31.8*pi (=99.9) inches. The MTB gear is much lower, but, the bike is heavier. When you say that you do hills better on your road bike, it's because the bike is lighter. But when you really need your very lowest gear, it's easier on the MTB because is has a much lower gear.

My small chainring is 42, my largest freewheel cog 24, so I have a minimum gear ratio of 48 (and I seldom use the 24 freewheel cog). I like hills and I go up faster than most people, but that's just the way I'm used to riding. I can do steep hills, but never face a hill longer than 1/2 mile. If I lived somewhere else, I might have to modify my technique and change my gearing. So don't get caught up in comparing your gearing or your hill climbing ability with others - just too many variables. If you have trouble climbing on your bike, you can either train more for hills or get lower gears. Training is cheaper, but your body is worth more than your bike, so don't blow our your knees because you're cheap or stubborn (that was a reminder to self).