"Do not use a cannon to kill a mosquito."

Yes, the tank is a rail gun monstrosity who can harm dragons with a shot. There will be a thousand places where the tank will either be moot or hindrances will keep it grounded. Primative teddybears were able to take out mounted platforms in star wars. A dragon in flight would be too mobile as an areal target to effectively shoot. A stray bolt of ligtning can short out systems, that is a 1 in a million chance of occuring, what happens when you face a storm mage and it is a 50/50 chance of getting hit by lightning?

Universal translators that analyze phonetic input to 'guess' a speech pattern, or a wizard who casts a translation spell on the crew. Goldfish you stick in your ear that consume the brainwave energy of those around it.

The crew may have a step-up, but they are still going to be epic lost and hungry after 3 days. Without locals to help them, they will die before they get home.