Eu não acho que é possível exibir um único Xclient diretamente em vários servidores X, dado como o X funciona.
No entanto, você poderia usar algo como XMX (um multiplexador de protocolo X) para multiplexar uma única sessão X em vários servidores X.
trecho do site principal: link
XMX is a standalone utility for sharing an X Window System session on multiple X displays. It allows users to see and interact with the same applications at the same time from different locations. XMX takes advantage of the networked nature of the X Window System by acting as an intermediary between X clients and X servers. In this way, XMX works with any X clients and any X servers, without the need to modify either.
XMX provides a WYSIWIS (What You See Is What I See) environment; it paints the same graphics on all participating displays. The shared client applications appear to each participant in a virtual root window which is subject to local window management. In this way, the shared X session coexists with each user's private X session.
The X client applications which are shared via XMX are unaware that they are being viewed or controlled by more than one user. Existing, single-user X client applications may be shared using XMX without recompilation, relinking or access to source code.
imagem dele em ação em um laboratório.