I would go with maractus. Not only does it have better defensive AND offensive stats, it's gives a good amount of coverage. Fighting type moves can already be covered by a superpower by flygon, and dark type crunch can cover for dark type moves for your later scrafty. Meanwhile maractus can learn grass type moves and many others. It can cover rock type weaknesses for gyrados and cinderace, as well as ground for flygon and cinderace, and (finally) water for cinderace. And if you are going for an eviolite scraggy, I wouldn't do it. While tanks do have a time and place in and in game team, it won't help as much until you get better tm and trs. Also, alcreamie can tank well, with high sp defense and with high levels, okay defense. While its attack is a bit lower, using moves like drain punch and petal bizzard give a wider range, and has much more coverage this way. I would do a set of petal blizzard, sucker punch, drain punch, and poison jab if you can. Otherwise, do something like sunny day with chlorophyll, to get better speed. I would replace it with drifblim, becuase I cant think of much coverage that it gives, as its mostly support, which isnt of much use while beating the story portion. So, I would recommend a maractus with maybe a span of moves, more offensive.
Hope I helped =)