What is the difference between the groups Ikhwan al-Muslimeen and Hizb ut-Tahrir?

I was once asked me for my opinion on the differences between the Islamic groups Ikhwan al-Muslimoon and Hizb ut-Tahrir. The two groups in my opinion are like chalk and cheese. They operate in different ways, focus on different issues, and have different underlying parafigms. I will limit myself to two different fundamental asoects in this answrr, their fundamental aims and methods: 1. AIM In aim, Ikhwan al-Muslimeen do not challenge the structures of contemporary nation states imposed by colonialism. The Iranian-American academic researcher Vali Nasr's chapter in the "Oxford history of Islam" details how every organ, institution and structure of modern Muslim nation states was set by external colonial powers - read more here). Instead they accepted them and tried to re-engineer Islam to fit within their tight constraints. Hence their aim is that of an Islamic state (dawla madaniyya), ie a partially Islamised secular nation state and not a Caliphate. This is the fundamental difference betwern the two parties. Hizb ut-Tahrir, akin to every classical scholar, confirmed in a detailed investigation by a consensus of leading scholars of the Ottoman Caliphate in 1925 (https://www.islamiqate.com/3435/ottoman-scholars-respond-raziqs-claims-caliphate-khilafah), that the ruling system in Islam is the caliphate, and to dispute this is blasphemy and not possible as an ijtihad due to overwhelming evidences to the contrary. This means the structures, institutions and organs of state have to be challenged and re-engineered before new policy formulation can begin. It is why groups adopting Ikhwan's aims tend to be coy in articulating them when asked - focusing on activities, keeping busy, rather than explaining where these activities will lead. 2. METHOD The second significant difference is methodological - Ikhwan has no fixed methodology, the ideology of pragmatism is used to adopt approaches relevant to time and place. It has been applied in different territories over the decades, visible in electioneering, joining autocratic regimes through to armed uprisings to everything in between. All have failed dramatically creating unintended consequences including loss of life, increased oppression, social disruption and furthering of their enemies agendas. Additionally they undertake social projects such as welfare, charity and education, with varying underlying aims and agendas. Hizb ut-Tahrir adopts the approach the messengers have always taken to reorient the nations they were sent to. This is detailed in full with the Prophet's (saw) activism in Mecca that lead to the Islamic state of Medina during his lifetime (https://www.islamiqate.com/3114/how-did-the-prophet-saw-call-people-to-islam-in-mecca). This highlights the sole project adopted by every messenger as being a proactive call for society to submit to God and live by revelation. No proactive projects involving charities, welfare or rebellion. Hizb ut-Tahrir adopts the seera as a starting point and then make necessary adaptations after taking into account any significant differences in his reality and ours, whether it be external dependencies on foreign powers and structures, autocratic secular nationalist elites, colonial demilitarisation of mass society and concentration of force in the military.