First and foremost, it's very refreshing to finally meet another rose hobbyist! This one is a passionate one I can tell!
I have not come across anyone who plant bare-root roses purchased from US. Indeed you are a brave one among us.
And thank you for bringing back these roses and introducing us to 5 exciting new roses. Kudos on having them loving Malaysian soil and kudos too for having done a great job of planting them right!
If I understand your question correctly, I believe you meant this:
These 2 roses (Texas & Cameron), although dissimilar in origins, they seem to share your one common concern; they both come from a temperate climate, which you kind of wondered if hardening process was necessary too for your Texas bare-root roses. Hmmm...
The answer to bare-root roses riddle
I think you know the answer too well already, since your 5 roses are thriving beautifully. :)
The reason you don't have to harden is because your roses are purchased bare-root. This means they are dormant when purchased. They don't have leaves on and not in active state of growing whatsoever. This condition is perfect for transporting, mass storing, custom & immigration processes, and etc.
In US, bare root roses are kept cool in storage and only available in spring and summer time when soil temperature is ideal for planting.
That is why your roses thrive, they start fresh from dormancy. Like seeds to seedlings. Grow only when they are ready and when environment is ready for them.
Cameron roses however are full grown roses, approximately 3-6 months of age when they are transported down for sale. Sold as plants in containers. They are not in any way dormant. They are very much alive and in active growing stage.
Any drastic change in temperature/climate can cause great deal of stress to them.
Given only few months of age with their roots just established, even the slightest humidity and heat change can make them wither and droop easily. A hardening process is required for continous survival.
So anyone would question, would Cameron roses be better done bare-root, then? Why can't our roses be sold bare-rooted in Malaysia?
Answer is very simple. Our roses grow and in active mode all year long because of our endless 'summer' climate. There's no winter for them to grow dormant.
Hope that answers! Enjoy your roses!