I think this is a characteristic protect the leaves from the sun posture. I rarely fertilize mine (which I should, but it seems to be the one thing that frequently falls by the wayside) and they are sitting under 50% shade cloth but in morning (with some early morning low angle direct sun) to evening full sun and their leaves look the same.
They are plenty happy, a couple bloomed before it got too hot. Mine have been seeing 110+ every day pretty much for the last 2-3 weeks. I water twice a week (so about the same frequency as you do), which in the height over summer here, is probably still not quite enough, but despite working from home the last few months it is all I can manage.
While Tarev is absolutely right with regards to them not liking to be wet all the time, in summer when it is both hot during the day and well above 60F at night you can water these quite frequently (you just want to make sure that your soil is drying out fast and mostly dry before you water again). I have been told by a long time cultivator Mark Dimmitt (I encourage you to check out his website about Adeniums - I think googling Mark Dimmitt - Adeniums will get you there, he has a book out on Adeniums, but a lot of useful info can be found on this website so while the book is nice, for tips on cultivation and what not it is not necessary) to almost treat these like tropicals in the height of Arizona summer (our night time lows are running in the mid 80s at the moment with day time highs consistently above 110 as mentioned).
One thing I would slowly start considering is to find a slight bigger pot, not too much bigger as that will drastically change how quickly your soil will dry out, but these are starting to look big enough that you might want to try and up-pot some time towards the end of summer when it is not quite so hot, but when they have a good period of growing season left to adjust to the new habitat. Given that you water frequently you might consider an unglazed clay pot, which will help with your soil drying out.
I am not sure how easy it is for you to do, but if you have access to some say 30 or 40% shade cloth you could put one of them under cover of some shade and see if this changes the posture of the leaves.