I dunno - wasnt it able to tank Blue Tears energy shots? If so it's nigh-on invulnerable, which is saying something...
As for developing an IS with an upper hand - well, the British were the only people to improve the Apache as well, taking an antitank gunship and adding Crazy Preparedness to it - for the first time, creating an aircraft that the
Americans are jealous of.
Let's not forget that when they put their minds to it they can think up lots of cool toys.