Natural language dialogue between multiple participants requires conversational grounding; however, the mechanisms involved are under dispute. Currently, two of the prominent grounding models are interactive alignment and interpersonal synergy. Using recurrence analysis, Fusaroli and Tylen (2016) simultaneously evaluated both models and showed that alignment is an insufficient explanation for grounding or for the teams’ task performance. However, their task and resulting dialogues lack the typical complexity of conversations or teamwork. Furthermore, the interpersonal synergy model was not clearly differentiated from other coordination-focused models of grounding with explicit foundations in strategy and intentionality (i.e., audience design, joint activity, perspective taking). Here we test recurrence-based models in a collaborative task that stressed the grounding process. Results support a coordination model of dialogue over the alignment model as a predictor of performance. Content-based mediation analyses showed that the coordination recurrence model includes critical aspects of strategic design and is not purely interpersonal synergy.