i. Big Tobacco is doing nothing illegal by producing and marketing cigarettes.
ii. Even so, regulators weighing up how to treat safer alternatives to cigarettes are often too harsh.
iii. No wonder people are cynical when they hear tobacco bosses evangelise about e-cigarettes.
iv. The industry has an inglorious history of lying about the effects of cigarettes on human health.

(i) sets the foundation by stating that Big Tobacco is not doing anything illegal in producing and marketing cigarettes. This provides a neutral starting point. 

(iv) follows by introducing the industry's history of deception, showing why people might distrust tobacco companies. 

(iii) builds on this distrust, explaining why people are cynical about tobacco executives promoting e-cigarettes—given their past dishonesty.

(ii) concludes by stating that despite this cynicism, regulators may be overly strict on safer alternatives like e-cigarettes, bringing in a critical viewpoint.

Hence, the correct order is (i), (iv), (iii), (ii)