We present BME-Daleel, our system for both Daleel 2026 Arabic argumentative discourse mining tasks. A joint Transformer predicts paragraph-level label presence and token-level BIO states; constrained decoding and domain-routed ensembles map spans to original character coordinates. Repeated out-of-fold comparisons gate domain specialists, while routing selected decoded outputs preserves other-genre rows exactly. Using organizer annotations and public pretrained models, our Closed-track system scores 0.7117 macro-F1 for paragraph classification and 0.7547 modified F1 for span detection.