I would like to start off to say that British is a good offensive nation, similar to Germans and Koreans. There is no dispute to that. Because the nature of this game is more to raiding and attacking, British seems overpowered because of it's unique range, but it is debatable of it's superiority as compared to other offensive nations mentioned. There are strong arguments why Germans are better than British, especially at later age when 15% applies to ALL troops, but i would not going into that here. I would like to bring up three points:
1) Calls for nerf in any game is detrimental in the long run. Didn't people complain about heavy Calvary before, and what happen to the Greeks? Didn't people complain about Romans before, and what happen to infantry units? It took them close to a year to buff back heavy calvary with the upgrades available in global age, as well as the research chapter 5 for fusilier in library. I rather support buffing nations which seems weaker as compared to nerfing those which seems stronger. I do support the further upgrades to tanks for French and Greeks, although it makes them beasts by having tanks with slightly lesser HP but half the troop space as compared to heavy tanks now. This brings greater balance to the game's unique units and I believe more should be done for those with infantry next. Furthermore, new nations might be released in global age which have a high chance to be the next OP nation to earn crown from existing players, adding British to the pool of seemingly under powered nations won't help to balance this game.
2) Are nations really under powered near "end game" in offense now, which is global age currently? Didn't those pros in global alliances complain of stalemates because offenses is too over powered? Unless all of them are 100% using British, it is an indication that near "end game" at this moment, all of the nations are viable and have sufficient offensive power to 5 stars any base even without the +1 range of their rifleman. These alliances claimed that the unbalance in offensive power compared to defense is not unique to a few skilled player but their entire alliance. Doesn't this some sort of "negate" the advantage British or other attacking nations have, since other nations are able to score five stars in the hands of mediocre global age players too? It is usually a fallacy to claim something as OP before we understand the balance towards the end game. In my opinion, defense need a buff in IA and above as a whole package, nerfing a single nation won't help balance the game in this aspect too, there will still be over powered tanks and other unique range and other bonuses. University research really helped in this aspect, players are starting to feel the pinch of unseen buff to towers and mortars which might be even more obvious towards the end of the year when more researches are being completed.
3) I do agree with the point raised earlier by
Radzeer. With the increase in alliance troop space but stagnant barrack troop space in global, alliance support is more important than ever before you can exploit any nation advantage by requesting for their uniques. A French nation can request 33 black watch from British to replace all their rifleman while still retain their awesome tanks. When everything adds up, they still have more 3 more troops! Similarly, Germans could do the same and retain the +15% damage to ALL units, I suppose its on top of the passive bonus damage which British or Korean range units have, but British can't import the increase damage or reduced rally advantage from them. Romans can replace all their rifleman too, but can British gain that 10% increased troop space from them? The only real advantage British has is its unique troops, which are pretty interchangeable with increase alliance troop space at later age, however it cannot inherit other bonuses from other nations like the 2 extra citizens from Chinese. Aren't a shortage of workers the real headache in this game?
Of course, you can argue that no one use alliance troops in every battle, especially in multiplayer! However, if you take normal multiplayer raiding, its another debate between the efficiency of British and French for another time.
To sum it up, the problem does not lie in British, but in the balance between offense and defense in the game, and the economics which is basically non existent. Nerfing a nation won't help to solve any of the bigger issues out there, as proven in the case with other nations which have gone down similar path.