Some people go for a pint or two at lunch time and return to work….not that far removed from the situation described by the OP.
If it’s impacting on work performance, have a quiet word suggesting he may want to tone it down a bit, esp from the point of view of client interaction.
Re smoking fags at work – I find Sort of strange how it’s seen as acceptable to feed addiction to cancer causing substances during work time and that employers actively support it by providing facilities.