I think in broad terms, the end goal of ecumenical talks and agreement for Anglicans is not to establish one big church organization with a singular way of doing everything with everyone in the same structure under the same bishops doing services or masses that are exactly the same. Rather, I think they are going more for agreements where as many churches or denominations as is possible continue in their separate traditions, and preserve those traditions, but recognize that each is the equivalent of the other and part of God's church, and can share clergy and resources, and work in mission together, where it makes sense to do so.
Someone mentioned the Episcopal Church's (US affiliate of the Anglican Communion) agreement with the Evangelical Lutheran Church of America (The largest Lutheran denomination in the US). I think the idea there is largely that, okay, in a broad sense the Episcopal Church is Christianity with roots in the English and Celtic traditions that has it's own traditions established on American soil in that mix as well, and that in a broad sense ELCA is Christianity with roots in German and maybe Swedish traditions and some other places that were further developed by many Lutheran denominations on American soil that added to the mix and then merged into ELCA (ELCA is I think the result of a lot of similar Lutheran denominations merging together or merging into ELCA over the years).
So, what you have there are ECUSA and ELCA recognizing that they are in broad strokes the same things underneath it all and that an Episcopalian priest and a Lutheran pastor are serving the same fundamental role and most could be candidates for positions in both Episcopalian parishes and Lutheran congregations with perhaps some extra instruction in the special traditions of each. However, because each group has special traditions and flavors to the way they do things that they want to preserve and think are worthy of preservation, they have sort of implicitly decided that rather than seek to literally become one church or denomination at a national level and compromise on all these traditions across the board and merge it together, that they are stronger having two technically separate institutions that preserve their traditions but recognize each other as equivalents of each other and that can in local areas where it makes sense be more flexible than they would be about to be without a formal agreement.
Okay, so, in practice, where can these agreements improve things for people in the pews?
Well, one thing is, if you have an Episcopalian parish and a Lutheran parish in an area that are both struggling to survive financially due to low membership and pledges, they could perhaps instead of each having a separate clergy-person, they could hire one priest or pastor from either tradition and each pay half his or her salary, with the clergyperson acting as a priest and celebrating the Eucharist according to the Book of Common Prayer at 9am in the Episcopalian parish, and then going over to the Lutheran congregation and doing a service as a pastor according the Lutheran liturgy at 11am at the Lutheran parish. Since ECUSA and ELCA both have the Revised Common Lectionary as their default lectionary now (A lectionary is a list of what the bible readings are on each Sunday) and the same liturgical seasons, the hypothetical priest/pastor in that situation would be able to prepare one sermon each Sunday and read it at both parishes after the same readings. The BCP lectionary is an option in Episcopalian parishes, and I think some Lutheran congregations are allowed to chuck the lectionary and just do random readings (I *think*, I'm not really sure how that works. Maybe I'll ask the Lutherans in their area. I do sense that they don't follow the lectionary as religiously, no pun intended, as Episcopalians and Roman Catholics do, but that they are sort of supposed to adhere to it mostly or something), but you've got that single official lectionary that clergy could use across groups because it is the same and the main or official lectionary of each church or denomination when called for.
They could even ditch separate church buildings and pool their money to jointly pay the expenses costs associated with a single church building they could share, too, at their own discretionary, if they couldn't afford separate church buildings.
Taken to an extreme, they could simply hold one big service that draws from both traditions, essentially a local parish or congregation that is part of both churches or denominations, and traditions, like the place a poster in this thread says she attends.
But in areas where two separate parishes or congregations can thrive with separate priests and pastors, they can still do it and be very distinctly in their own tradition, with clergy from their own tradition's seminaries and so on and so forth. And just recognize that they are all the same beliefs, mostly, underneath.
The idea is that you don't have to look and act identically and have identical traditions to be the same faith underneath. You also don't have to have the same bishop in a given area. But it's also that ultimately these churches and denominations can be stronger when they are one in the sense of a sort of spiritual unity and share communion and priests and all sort of things in common in areas where it makes sense to do so.
I'll bet the Church of England and Old Catholic situation is kind of similar.
