Retrieving available lists or campaigns via the SOAP API?

So I found out about getCampaignsForSource ... I used it to retrieve campaigns for the two sources SALES and MKTOWS but there are far fewer campaigns than I would expect to see.

I also see that this issue has been brought up before:

https://community.marketo.com/MarketoDiscussionDetail?id=90650000000PITbAAO

Is there actually any reliable way to retrieve all available campaigns?  Or is the SOAP API just broken in this regard?

So I realized that only one of our campaigns has "Campaign is Requested" on its smart list ... it is set to Sales Insight, and it is returned properly when I set the source to SALES.

I assume, but have not tested, that if I set "Campaign is Requested" to "Web Service API", I can retrieve it by using the source of MKTOWS

I noticed that there is a third entry in the "Campaign is Requested" value dropdown, which is Marketo Flow Action.  Are campaigns with this "Campaign is Requested" value not retrievable with getCampaignsForSource?

Jim,
The getCampaignsForSource function returns a list of available Marketo campaigns that can be used as input parameters into the requestCampaign function. If the trigger is set to "Marketo Flow Action", this campaign cannot be requested through the API and hence is not enumerated here.

Raj