Good comments above, I'll amplify and expand.
TBR has good dive operation. They have one of the best naturalist DMs on the island, Osman.
There is absolutely no shore dive. Their website is reflective of the reality: this is a resort that happens to offer diving.
You asked about the differences between "Northside, up East" (as it is known) versus West and South. In short, it's deep up near TBR. Not at all hard to get to 130' for the inattentive. Oh, you said they were newly minted divers? Are you just are a trip leader or a dive pro? That might be an important distinction. It is in shadow, and because the West North is what gets smacked by storms, it is not as florid. The upside is that this has caused interesting shapes, chutes and all, another attractive feature for new divers...this is something they can see and recognize.
Weather in that zone can be predictably perfect March > September.
The diving near FIBR is much more in tune with newer divers skills. Also having an equally good dive op, but the FI resort itself has lost its compass. TBR can be spotty, but if your group has a good cohesive sense of humor, it should be tolerable.
Looking for "big stuff" on Roatan is kind of a waste of time. It is, however, a major goal for new divers because this is what they are able to see (so far). New divers will get their checklist of the obvious critters quite quickly using AKR or a West End type dive op as its in the Roatan Marine Park. South side is unsurpassed in the Caribbean for shallow micro/macro in the 55' to surface zone- extremely shallow.
What to do then about diving at TBR?
Tell your DM to show you the cool little stuff. That will keep you above 80'. If you are actually, really, doing 3 dives per day, use nitrox. Encourage your new divers to accept assistance (actively seek it) for buoyancy skills. Ask for shallow hard bottoms until they prove their abilities, then don't be afraid to split up the group for their own safety.