I think you should definitely be able to have some SMB in your small 1/2 ac pond providing you do some important things.

Firstly - be very careful that the captured SMB are not stressed when you catch, and hold them before traveling home. Make sure they have good aeration in the travel holding container AND do not over crowd them in the holding tank; fewer numbers are always much better than too many in the tank which causes undue stress that can kill them later after pond release. My rule of thumb is too much hauling water is always better than too little. Remember the pond life and habitat will be a lot different than the stream life conditions. This in itself is a stressor that reduces chances of survival when these SMbass grew up in stream conditions.

Secondly for each SMB that you plan to add to the pond remove at least 2 or three or better 4 LMB for each new SMB added. LMB are big BULLIES and will strongly compete for habitat spaces and the good foods against the newly added SMbass. You want to make sure that the new SMbass have plenty of foods in the new pond conditions; thus reduce their competition. LMB who are aggressively eating all the good available pond foods heavily contribute with the new bass who could be or would be starving. The smallies need to eat well to maintain body weight and compete well with the LMB bullies. Thus the new SMB need to eat well to adjust and survive pond life with more aggressive LMB present.

Thirdly - The more LMB that you later ANNUALLY remove while the SMB are in the pond, the better the smallies will survive in your 1/2 ac pond.

Fourthly - Every year or two as you diligently annually remove some LMB then try to add 2 - 3 more SMB from the stream. This keeps the SMB numbers in good density which I assume is your goal for the pond.