Advice for team

I'm working on a team, but i need some advice. here's my team so far, with question marks on fields i'm not sure of.
Slowbro @ Rocky Helmet

Bold

252 DEF/252 HP/4 S.ATK

Slack Off
Scald
Thunder Wave
Iron Defense

Chansey @ Eviolite

Calm

252 S.DEF/252 HP/4 ???

Softboiled
Seismic Toss
Toxic
???

Gallade @ Galladite

Jolly

252 ATK/252 SPD/4 S.DEF

Night Slash
Bulk Up
Drain Punch
Psycho Cut

What do you think? What else could i add? do i need improvements?

I'm thinking of adding a banette to my team. What do you guys think?

(Disclaimer: I'm not a competitive battler, but I'd like to be)
I don't know about adding the banette, unless there is a specific strategy that at makes it viable, I doubt it

how about a guts moveset?

i've added a crobat to my team

Crobat @ Flying Gem

Jolly

252 ATK/252 SPD/4 S. DEF

Acrobatics
Cross Poision
Confuse Ray
U-Turn

Try heal bell or stealth rock for Chansey's forth move, heal bell will heal your team of status conditions while stealth rock is just a good support move also add the 5 extra evs into defense to give Chansey just that much more bulk. Change Slowbro's Scald or Thunder Wave, you can only burn or paralyze but not both making the presence of both moves on a single pokemon redundant, by replacing Scald with Surf or Thunder Wave with Psychic, Shadow Ball, or another move will just optimize it better. You have defense and physical offence covered nicely so think about adding a good special attacker, look into something like Rotom-H, Volcarona, Cacturn (a personal favorite) or whatever else you would like just be careful about pokemon that are weak to electric or ghost type moves since you have two pokemon who are weak to both of these. I would also mess around with Crobat's Confuse Ray, it isn't a bad choice but there might be something better you can do with it. A vary solid start and I hope that this team continues to grow and improve.