Types and Team Building

When you're making/planning a team in a game, are their any types you're lenient towards having doubles to? Or where their primary type overshadows their secondary type so much, you don't really consider the second much?

Like... doing a run through of Platinum with Kanade right now, and I have both a Roselia and Croagunk on my team. The poison nature of Roselia seems... "passive", so I don't really mind having doubles of it, much. Granted, I also have a way to counter Psychics, buuut... and, of course, I mean in-game more than competitive, as there's a big difference with this in competitive.

The types I find passive/double upable are: Fighting, Flying, Normal, sometimes Steel, sometimes Ice, sometimes Poison, sometimes Ground, and sometimes Bug.

I usually have a mix of types in my team and dont really like to have 2 of the same type unless it is a double type.

These days I try not to have duplicate types, unless I'm trying to act like a gym leader or something and go throughout the game with one type, which isn't often. xP

But I definitely agree about the Normal type being passive. Especially with all the Flying Pokemon, I don't mind having duplicate Normals.

One important thing is to calculate how much and what kind of types you can beat with your pokemons. Team including (Ground & Rock, Ice & Water, Dark, Fighting, Flying, +1 random pokemon, could defeat any other type.

Golem (ground & rock) > bug, fire, flying, ice, electr, poison, rock, steel.
Cloyster (Ice & Water) > fire*, dragon, flying, grass, ground, rock*.
Umbreon (Dark) > psychic, ghost.
Hitmonchan (Fighting) > dark, normal, steel*, ice*, rock*.
Pidgeot (Flying & Normal) > bug*, fight, grass*.

And you have one more spot for your favourite pokemon. :)
By the way - watch out for weekness too.

*dublicates

Sometimes 2 of my team members have the same type because I like both Pokemon so much to not be passed up for a team slot.

When I plan teams I decide on type, design, and weaknesses factor.

I always make sure I don't duplicate on types and also use Pokemon I like the look and moveset of.

After I do that, I have to check for any glaring weaknesses on my team so I can be prepared for that type I am weak to.