It is not so much that the A/C is weak is that it is too small for the heat load. The power available to RVs limits air conditioner capacity, and if your RV is too big for a single air condition, it needs more than one. Two units are fairly common once past 28-30 feet of box to cool, and three are real common at 40-45 foot length. I've seen as many as five RV air conditioners installed on high-end coaches that have the powerplant to run them, this helps manage climate for different zones.
A travel trailer that size in a warm climate, in sunlight, probably needs at least two units running to cool it down and maintain "cool" during daytime. If it needs two, it should have come with 50 amp service to run two. Not many travel trailer brands or models come this well equipped for heat, because us shoppers tend to favor low prices.
Heartland is a relatively new company, so I don't know where they've positioned themselves in the market. I don't think they are in luxury market only, so low price model lines might be less well equipped than what we expect in a premium RV. Wilderness is a lightweight model line, so likely to have thinner walls, floor, and ceiling to keep weight down.
At 32 feet, with a big slideout to leak additional heat, the model you are looking at should really have two A/Cs. My friends with a similar size Jayco lightweight find that they can't cool it down much past 85-90 in the summer sunlight, parked out by the lake shore, so in the daytime they will come sit in my heavier RV (walls 50% thicker, ceiling 4-6 inches of foam) which I've had the sense to park where shaded by trees most of the day.
