Can I use several active link to same table?

Here is my scheme:

The last picture shows the my issue and how I fix it. But I not sure is it a good way.

Looks like Anonymous propouse the same way. 

But what do you mean by "if you query that will provide the output what you are looking for" ? 

db sctipt just in case

CREATE TABLE [dbo].[Order](
	[OrderId] [int] IDENTITY(1,1) NOT NULL,
	[CustomerId] [int] NOT NULL,
	[CashierId] [int] NOT NULL,
	[Total] [money] NOT NULL,
	[Taxes] [money] NOT NULL,
	[Discount] [money] NOT NULL,
	[Tips] [money] NOT NULL,
 CONSTRAINT [PK_Order] PRIMARY KEY CLUSTERED 
(
	[OrderId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

CREATE TABLE [dbo].[Person](
	[PersonId] [int] IDENTITY(1,1) NOT NULL,
	[FirstName] [nvarchar](255) NOT NULL,
	[LastName] [nvarchar](255) NOT NULL,
	[FullName]  AS (([FirstName]+' ')+[LastName]),
	[IsCustomer] [bit] NOT NULL,
	[IsCashier] [bit] NOT NULL,
 CONSTRAINT [PK_Person] PRIMARY KEY CLUSTERED 
(
	[PersonId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
ALTER TABLE [dbo].[Order]  WITH CHECK ADD  CONSTRAINT [FK_Order_Person] FOREIGN KEY([CustomerId])
REFERENCES [dbo].[Person] ([PersonId])
GO
ALTER TABLE [dbo].[Order] CHECK CONSTRAINT [FK_Order_Person]
GO
ALTER TABLE [dbo].[Order]  WITH CHECK ADD  CONSTRAINT [FK_Order_Person1] FOREIGN KEY([CashierId])
REFERENCES [dbo].[Person] ([PersonId])
GO
ALTER TABLE [dbo].[Order] CHECK CONSTRAINT [FK_Order_Person1]
GO