TPL Dataflow - Parallel&Async processing, while keeping order

I created a TPL Dataflow pipeline which consist of 3 TransformBlock's and an ActionBlock at the end.

var loadXml = new TransformBlock(job => { ... }); // I/O
var validateData = new TransformBlock(job => { ... }); // Parsing&Validating&Calculations
var importJob = new TransformBlock(job => { ... }); // Saving to database

var loadingFailed = new ActionBlock(job => CreateResponse(job));
var validationFailed = new ActionBlock(job => CreateResponse(job));
var reportImport = new ActionBlock(job => CreateResponse(job));

loadXml.LinkTo(validateData, job => job.ReturnCode == 100);
loadXml.LinkTo(loadingFailed);

validateData.LinkTo(importJob, Job => Job.ReturnCode == 100);
validateData.LinkTo(validationFailed);

importJob.LinkTo(reportImport);

Each block will fill the Job-object with the processed data, since i not only need the data itself but also general information, that i need for the response messages. I pretty much add a path to an XML and get a Response-object with information if everything went right.

How can i achieve so that if two or more files come in that take some time to read from HDD, it reads both files parallel and async, while keeping the order they came in? If file1 takes much more time, file 2 would need to wait for file1 to finish before i pass the data over to the next Block and then it will also start validating the data parallel and async, but also here keeps the order for the next block?

Right now it looks like even if i call SendAsync to the headblock, it will sequentially process all files.

EDIT: So i wrote a little test class for my purpose of the pipeline. It has 3 stages. What i want to achieve is the first TransformBlock to keep reading in files as they come in (SendAsync from a FileSystemWatcher) and output it when done in order they came in. Means if File1 is a large file and File2+3 comes in, both will be read in, while File1 is still being processed, but File2+3 will have to wait until it can get send to the second TransformBlock, because File1 is still being read in. Stage2 should work just the same. Stage3 on the other hand needs to take objects generated from File1 and save into to database, which can be done parallel and async. However, objects from file1 need to be processed before file2 and file3. So the file contents as a whole need to be processed sequantially in order they came in. I tried doing that by limiting the 3rd TransformBlock with MaxDegreeOfParallelism and BoundedCapacity both set to 1, but this seems to fail and not really keep the order in the Console.WriteLine's

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using System.Threading.Tasks.Dataflow;
using System.Xml;
using System.Linq;

namespace OrderProcessing
{
    public class Job
    {
        public string Path { get; set; }

        public XmlDocument Document { get; set; }

        public List