The problem is that where they connect at that curved portion, they technically aren't actually connected... Nor when they're "wall-to-wall" and have that back raised portion (like a little chunk of wall, I just call it the "back" of the base), as they're just resting against each other but not technically connected utilizing the tabs sculpted into it...
Had Hasbro made them so they just had those tabs on all 4 sides, that would've made sense so they could literally snap together in any form... It'd be like this plastic stuff called "Sport Court" they use for things like Dek Hockey where the floor/surface is just plastic flooring that interlocks at all 4 sides perfectly with another piece... I really don't get why Hasbro sculpted those bases so they're not able to connect on all 4 sides smoothly. The lava and foliage bases are cool, especially if you could work them into a larger set-up so they blended nicely, but the tiling/deck plating surface is just kinda confusing the way they did it. Too bad... It would've been great to accumulate a ton of them and floor a diorama with it totally. I wanted the bases that the Imp. Dignitaries came with to do that but they never used that base again for some unexplainable reason.
The irony is that they finally fixed the rectangular bases and they DO interlock fairly well (little loose/flimsy but they work). You can really display with those nicely if you have the ones that interlock well together, however they leave gaps between the bases and have that big SW logo on it... Do that with just that grid-work sculpted into it, like Deck plating or a Coruscant Street or something, and that's pretty damn cool. I'd buy just those if they were offered up then.