Yes, I think (healthy) treats are very helpful. Getting them to associate you with something good will be a big help. Just hand-feeding them their daily pellets rather than putting them in a bowl has always worked wonders with new buns for me. Being near with them without trying to touch them or force them into anything will let them see that you're not someone they have to fear. Once they've learned that, they'll likely start approaching you on their own (especially if you have food!), though some bunnies just aren't very interested in human interaction and never will be. It's still great fun to watch those bunnies go about their day, though.
If they're young, there's still time to get them used to being handled too, so don't be afraid. That's one of the worst things I did, honestly. We were so worried about picking them up, they never got used to it. Now they're older, and they don't like it as much as if we'd had picked them up consistently when they were babies. It's not too late, but it would've been easier! A confident hand is really important, don't be afraid or hesitant, they will pick up on it (all animals will!)
Even after 7(ish??) months, my rabbits aren't what I would call "cuddly". They're very hands-off. They'll tolerant of a few pets, or they'll try to use my lap as a launching pad, but they'll rarely ever sit on my like a cat. They mostly like to sit under me or on my feet (especially when I'm walking!)
To be honest, I don't think it would have made a big difference if you had picked them up a lot when they were younger. The age at which bunnies should get used to being handled is quite young, around 5-6 weeks, while they're still with their mum. If that hasn't happened, by the time they've moved into their new home, it's unlikely that they're ever going to get used to it to such a degree that they won't mind it. Baby bunnies are often still fine with it, but as they get older that normally stops. Usually what happens if you pick bunnies up a lot to make them get used to it, is they might eventually give up fighting it because they learn there's no point, so they'll stay still, but they're still afraid. All the picking up will cause them stress, and I wouldn't recommend it, especially when they're still learning to trust their new human(s), because it will be nearly impossible to get them to trust you if you keep forcing them into something that scares them.
There are of course exceptions, and bunnies who need a lot of hands-on care can be(come) fine with it, but bunnies, on average, just don't like being handled and never will. It's better to minimise the instances when you need to pick them up rather than pick them up a lot with the aim of them getting used to it. You can lure them into an box or a carrier, for example, or do stuff on the ground. If they don't get picked up regularly, they're also less likely to run away when you do ever need to pick them up, because they're not expecting it. If Chika and Cinny find their weekly clip and groom so stressful that you need to protect your arms, I would try to see what you can do to make it less scary for them, or do it less frequently.
Chika and Cinny sound like very typical buns! Most bunnies won't sit on your lap like a cat, and of all the bunnies I've lived with, only one has been cuddly. I think the forum might give a bit of a skewed picture sometimes, because people will talk about petting and cuddling the buns who like it, but we don't talk about all the cuddling we're
not doing with the bunnies who don't!
.
. To be honest, I’m really pleased with the progress they’re making. We’ve had them just over 2 weeks and they’re already happy to come over and sniff me whenever I go out to them. One even jumped onto my lap recently! I stroke them in the mornings when I go out to feed them and they don’t try to run away, they seem quite relaxed. I hope I’m not reading their body language wrong! I go out to see them throughout the day and they aren’t as happy to let me stroke them at those times so I just leave them if they run away when I try and just sit with them instead.