Times on that table are remarkably consistent to my own
I ran the Belfast half in Sept 22 in 1:42 went on to run Dublin Marathon (disaster run) in 3:51- recently completed Antrim Coast on a brutal day in 1:29 in between ran two Belfast marathons, first in 3:36 and second in 3:17
I have been really consistent with my running and did have some weight to lose that helped
If you have done 1:51 for a half, and can commit to the training - I'd say 3:40 is possible
I ran the Belfast half in Sept 22 in 1:42 went on to run Dublin Marathon (disaster run) in 3:51- recently completed Antrim Coast on a brutal day in 1:29 in between ran two Belfast marathons, first in 3:36 and second in 3:17
I have been really consistent with my running and did have some weight to lose that helped
If you have done 1:51 for a half, and can commit to the training - I'd say 3:40 is possible