You can go with a 3 Warrior team + Healer / 2 subs or 3 Knight + Healer / 2 subs team.
Audette is a spear user which I found to be typically rare for what we got to work with right now so you can probably equip a decent weapon if you're looking to invest. Maurice is pretty much your filler here. Their skill is pretty much identical in what it does, i'm not sure of the damage difference but it's the same effect more or less, Robby is the key here for AOE clearing for 1 mana as well as higher movespeed in combat. As for healers, I personally use a Melvina and the heal and cure poison is wonderful so all you really need do for her is to level up for the cost, Kate is sufficient for the most part until you can use her in your team. For subs, I'd put in Nicky for the EXP Boost and your hero. Of course consider leveling them up before setting them as your primary squad and the like if you haven't already.
Haruaki is a good unit that I still use, but if you only got one copy of him then you'd want to put him on the side since you can easily get more Dusty's and limit break him and max him out. Once you do that he'll be stronger than a level 40 Haruaki. A limit broken Dusty has 5099 ATK/3800 HP while a normal Haruaki has 4200 ATK/4150 HP. Hero is good for cost and is a filler pretty much. You can put him on the side if you want to.
I opted for Iris over Ryubia for a small reason. Ryubia skill cost is 2 mana while Iris is 1. You can however use both if you do not want to use your hero(throw him in the subs) They both have similar skills except Iris does light damage compared to Ryubias moderate damage. There normal max levels have miniscule differences and I generally like Iris skill better(gold gains) and on another note Dusty gives gold gains as well. Leveling cards become quite a money consumer so once you're higher level you can make a gold team just to run on the weekends for substantially larger gains, so it's much more beneficial to hold onto these cards in my opinions. Of course, your healer would most likely be Kate and switched over to Melvina once you have enough cost to hold them. Subs would once again by Nicky or your Hero. If you're going to use Ryubia then put Iris into your sub.