Spirit link is only really annoying until you have a fast mana debuffer. (Even less so if you manage to get 2). Then Spirit link is really just a wasted spot in defence.
Most annoying for me is centrally placed strong/tank healer with buffs or debuffs (e.g. boldtusk). If a team has one of these with one or more accompanying ‘incidental’ healers (i.e. heal and do something else) then they become very annoying to beat. You can’t help but charge their mana and they keep topping themselves up.
Only real way out is to save your big hitter specials until you have more than 1 to be able to focus on one of those and take them out in a single round. Otherwise you risk trying and just topping them up again. I lost to a far ‘weaker’ team in power to this combination and then lost again in a re-try. I was fit to burst!